Nu is also an uncommon archaic reading of the kanji 寝 (sleep), as the base form of a verb equivalent to modern 寝る (neru). Maybe there's a connection, since they always seem to be dozing off.

The weaker type that appears in the Dinomen Hideout and elsewhere.

In retrospect, this is a fairly awkward name. I probably should have just called them "Saurians" or something like that.

Short for "marmoset", I think. Possibly related to "mammal", but that seems like a stretch.

If you visit the sewers as early as possible, magic attacks are limited to Crono's Wind Scythe (unlikely to be worthwhile due to his low Magic, especially since 150 physical defense isn't much higher than 127) and Lucca's Flamethrower. Their Blaze Wheel combo deals no more damage than Flamethrower and Crono's Whirlslash independently, so Crono almost might as well just attack normally. Of course, if you wait until late in the game to come here, it's a curbstomp.

The more powerful purple ones, found in Magus Castle.

The 15th letter of the Greek alphabet, and identical in appearance to the Latin 'O'. According to The Chrono Compendium, this is the beefy guy with the mace and plum cape and helmet that summons some monsters in the Abyssal Temple stairway area, then runs away. You can't fight it without modification. Does nothing in combat if hacked in. 455 exp, 8 TP, 600 G.

As noted in the story section, steal from these for Speed Capsules.

Unused. Uses Lavos Core (humanoid part) sprite. Does nothing in combat. 151 exp, 8 TP, 370 G.

Possibly related to じゃり (jary, gravel).

The blue and green varieties have the same name in Japanese.

Fortunately, you're not expected to take the tamer out directly, but if you're going to try anyway, stick with magic attacks.

まる (maru) is 丸, round. The name as a whole bears a strong resemblance to アルマジロ (armadillo), and the monster resembles one too. Thanks to kahran042 for pointing this one out.

わる (waru) is 悪, bad/evil. Luckily, "ball" and "bad" are similar, much like まる and わる are.

Lavos part imitating one of Giga Gaia's arms.

This resembles ほうおう (houou, firebird), but is closer to ホーホー (HOU HOU), the noise an owl makes (thanks to Hyena 20 for the latter). A Hwoot-Hwoot will turn into a Bwoot-Bwoot when low on health.

No apparent meaning beyond the obvious similarity to the previous name. An odd bit of trivia is that it takes negative zero damage from Fire. This is no different from normal immunity except that the zero displays as healing (in green).

Lavos part imitating one of Giga Gaia's arms.

Replaced with a Jarrian when HP runs out, unless killed on a counter attack.

No apparent meaning. Spelling chosen based on ジャンヌ being the Japanese rendition of Jeanne.

Unused. Extra Lavos mode? Has the same stats as Melfikk's torso. Uses Lavos shell ground auxiliary part sprite. Does nothing in combat. No rewards for winning.

噛む (kamu) is a verb meaning "bite", but ツインカム (TSUIN KAMU) also refers to a "twin cam", an internal combustion engine with two camshafts. Credit to Hyena 20 for inspiring me to reinvestigate for puns on this one.

Unused. Extra Lavos mode? Has the same stats as Melfikk's legs. Uses Lavos shell ground auxiliary part sprite. Does nothing in combat. No rewards for winning.

A pink octopus that never appears as an enemy. Can't fight without modification, but it's functional if hacked in. 146 exp, 4 TP, 250 G.

First battle. Likes to spam Halation.

Rafflesia is a genus of giant parasitic flower. It's also a fairly common foe in RPGs, and often badly misspelled.

たかねのはな (takane no hana) also figurately means something unattainable that can only be admired from a distance.

Absurdly weak against laser beams (and Dark magic in general), taking roughly eight times typical damage.

Probable pun on "bone man".

This tougher Bone Nam forms when one of the basic ones fuses with an Id after taking damage.

At least, that's what the name sounds like, even if it doesn't make much sense.

Giga Mutant's "foot".

Tera Mutant's "foot".

The Juggler raises magic defense but drops physical defense in response to magical attacks, and vice-versa.

The name doesn't seem to mean anything, so I just picked a spelling that looked good. Or evil. Whatever. Anyway, this monster is the core. Use Aether, Dark, or Fire attacks to keep it alive so that the torso and legs will remain relatively inactive and unable to recover their defense.

Unused. Extra Lavos mode? Has the same stats as Mother Brain's Displays. Uses Lavos shell floating auxiliary part sprite. Does nothing in combat. No rewards for winning.

The stronger brown type, which appears in Tyran Castle.

The Sentinel will eventually shift its shield aside, exposing itself and turning into monster #63.

Is that supposed to look like "Yo, dude" with a moved space? Regardless, this is still the same monster (conceptually) as the one above, just with the shield down, so should have the same name.

Kahran042 adds that according to Ultimania, the name (pronounced like A U) plays on Au (gold) as well as 英雄 (eiyuu, hero); note that the shield looks golden. I'd appreciate suggestions on a better way to imitate the wordplay in English.

Again, same monster conceptually, just with the shield off to the side.

It's unclear what the point of the magic and elemental defenses is, since all battles with these prevent all skill and item use.

Unused. Uses Lavos shell floating auxiliary part sprite. Does nothing in combat. No rewards for winning.

A Klein bottle is sort of the next-dimensional equivalent of a Mobius strip. Because of the nature of the shape, it can't actually exist in fewer than four dimensions.

"Beetle" is clear enough. The first part, not as much, but it appears to be a shortened form of エンシェント = "ancient".

In the fashion of martial artist monks.

The weaker blue ones, found in Manoria Abbey and Hekeran's Cave.

Snake monsters in the same area have a tendency to eat these to heal, hence the name.

Drops 2 Fangs. The three types of Primeval Frog seem to be identical except for what they drop.

Drops 2 Horns. The three types of Primeval Frog seem to be identical except for what they drop.

According to The Chrono Compendium, these are the rather paranoid frogs you see in the Underground Waterway Ruins talking about switches and bridges. You can't actually fight them without modification, but the enemy is functional if hacked in. 127 exp, 4 TP, 200 G.

These will fire lasers at any Ratler in the same battle until none are left.

Since the Debugger is the same general type of robot as the Mouse Hunter, it seems likely that the sort of debugging they're meant for involves exterminating pests, not the perhaps more obvious meaning of correcting computer code.

Killing the accompanying Billion will let the next hit break Million's defenses to normal levels.

Unused. Extra Lavos mode? Similar stats to Son of Sun's flames. Uses Lavos shell floating auxiliary part sprite. Does nothing in combat. No rewards for winning.

ガッサ (GASSA) likely has a connection to がっさく (gassaku, collaboration), especially given the cooperative attack with the winged primates. Thanks to Hyena 20.

No apparent meaning beyond "moss".

The Japanese is written a bit oddly, so I spelled the English oddly too. It's also unclear what the magic and elemental defenses are for, since you can only ever use normal attacks on them anyway.

Unused. Uses Lavos shell floating auxiliary part sprite. Dies instantly in combat thanks to having no hit points. No rewards for winning.

One of the four mythological Chinese gods who govern the four quadrents of the sky, Genbu (玄武 in kanji) appears as a tortoise and rules over water and the northern sky.

The first Genbu loses its covering and becomes this second form when hit.

No apparent meaning, other than the similarity to monster #101.

These are the fake save points that appear in Magus Castle.

"Sand" makes sense, but there's otherwise no apparent meaning except the similarity to #99.

Unused. Uses Lavos shell ground auxiliary part sprite. Does nothing in combat. No rewards for winning.

Remember that physical immunity only prevents physical attacks from hitting. The physical portion of hybrid combos that always hit, such as Ice Sword, will still inflict normal damage.

Wind Scythe is relatively effective, but with 10 HP, they won't last all that long regardless.

As with Acid, Wind Scythe may help. Just try not to let Acid and Alkali react with each other...

Drops 2 Feathers. The two types of Rainy seem to be identical except for what they drop.

Drops 2 Flower Petals. The two types of Rainy seem to be identical except for what they drop.

The "head" of Mini Lavos R, found in the Black Dream.

The shell. Kill the "head" and this dies too.

No apparent meaning.

Version without hammer. No apparent meaning to the name.

In all caps since モンスター would normally be written in katakana. According to The Chrono Compendium, these are the monsters that fall off the conveyor belt in Vinnegar's Manor. You can't actually fight them without modification. Does nothing in combat if hacked in. 348 exp, 8 TP, 650 G.

Burn the hammer with any Fire attack to turn these into the weaker variety. Failing that, magical attacks work somewhat better than physical ones. The name has no apparent meaning.

Ogre with scimitar.

Ogre with crossbow.

Unused. Uses Lavos shell ground auxiliary part sprite. Does nothing in combat. No rewards for winning.

Unused. Uses Lavos shell ground auxiliary part sprite. Does nothing in combat. 382 exp, 8 TP, 800 G.

No apparent meaning. デッカ (DEKKA) might come from でかい (dekai, huge).

In a peculiar reversal, the NA version imitates the name of a similar (but non-combatant) monster, when it more typically gives different names to monsters that originally have the same name (and all too often are the same creature).

泥食い. Mud-Eaters gain attack power each time you hit them, so you should favor powerful combos.

The magic defense and elemental affinities are irrelevant since you can't use skills or items anyway.

This is an alternate Nu that has no rewards for winning, nothing to steal, and less magic power than usual. I think they're mixed in with the regular type for the battle in the secret room in Enharsa.

No apparent meaning.

No apparent meaning. As noted in the story section, rob them for Magic Capsules.

Jogging sound effect. The kid with the similar name is タータ.

Huh. I never thought of these as mechanical. Or was it confused for another Version-type monster?

Thanks to Mew seeker for noticing that the pronunciation matches the French word scarabée, which unsurprisingly means "scarab".

The name comes from デブ (DEBU), a rude term for the overweight. Thanks to Hyena 20.

Obviously, you're really not expected to hurt him, though Tail Twister and Poyozo Dance will inflict some damage.

No apparent meaning.

Drops 2 Feathers. The three types of Primeval Frog seem to be identical except for what they drop.

As bland as they come, except for the counterattack. Makes a good introductory battle.

Imitates the element last used against it, but note that switching costs it a turn.

All attacks against Gran are countered with their version of X-Slash...

...but attacks against Leon are not countered at all. So hit him!

When they charge tornado energy, use Crono's Wind Scythe to disrupt it, and never mind the damage penalty.

No apparent meaning.

No apparent meaning. Any Aether attack except Wind Scythe will lower his defenses until he purges the electric energy.

His defenses lower when hit with Aether attacks other than Wind Scythe, and raise when hit with anything else, or when he purges electric energy after being shocked.

Magus Castle version, without sword.

Magus Castle version, with sword.

Magus Castle version.

Three-on-three battle.

Short for "mutant", of course.

Three-on-three battle.

As fought on Zenan Bridge.

Any battle where he's in that barrier. It's theoretically possible to take him out directly, but pointless. Just hit the cranks and get it over with. If you want to try anyway, a lucky hit from Ayla at high enough levels will do for him...

Three-on-three battle.

No apparent meaning.

Saurus, of course, is a common suffix in dinosaur names, and comes from a Greek word for lizards and reptiles.

ニクス appears to draw from デイノニクス (Deinonychus), a dinosaur that these resemble. The "nychus" comes from a Greek word for "claw". Thanks to kahran042 for noticing this and pointing it out to me.

Like the memo says, kill it with weapons.

Battles Cyrus in Frog's flashback, and doesn't appear elsewhere. You can't actually fight him without modification, but the enemy is functional if hacked in. 10 exp, 1 TP, 100 G.

坊主 (bouzu) refers to a Buddhist priest, but can also be used like "kid". Appears only in the developers ending. Can't fight without modification. Does nothing in combat if hacked in. 30 exp, 2 TP, 450 G.

The head in the second battle.

One of Zeal's hands. Counters everything with Lifeshaver (HP to 1). Steal anyway for a Prism Dress.

One of Zeal's hands. Counters everything with MP Buster (steals all MP). Steal anyway for a Prism Helm.

This monster is just the legs.

Junkdragar's torso.

Melfikk's legs. Water attacks will lower its defense. All other hits will raise it, but only if the core is dead.

Melfikk's torso. Water attacks will lower its defense. All other hits will raise it, but only if the core is dead.

Mega Mutant's "foot".

Solo battle.

Solo battle.

Its defenses drop to normal levels when charging flame breath, which occurs after Azarla is beaten or enough time passes.

Mother Brain becomes significantly more aggressive if all the Displays are destroyed.

Dies instantly in combat thanks to having no hit points. The sprite is loaded along with the main Mother Brain sprite, and looks to be the outer part of her cloak, so it's most likely used solely to complete her appearance.

Could also be the name Daigoroh.

Imitating Guard Machine.

Imitating Hekeran.

Imitating Junkdragar (torso).

Imitating Gran and Leon. If it lasts long enough to charge tornado energy, use Crono's Wind Scythe to disrupt that.

Imitating Nizbel. Any Aether attack except Wind Scythe will lower its defenses until it purges the electric energy. You'd better have Crono, the Magus, or Robo's final tech available... Oddly, its magic is lower at 27 than the original's 33.

Imitating the Magus. Temporarily loses magic defense when hit with the Grandleon. When hit with anything else, switches to a random elemental vulnerability and uses a spell of that trait. At lower health, its defenses drop to normal levels as it prepares to cast Dark Matter. Oddly, its magic is lower at 3 than the original's 8.

Imitating Dragon Tank.

Lavos interior, torso. Its defenses drop to normal levels when it activates after enough time passes or both arms are killed.

Lavos interior, left arm (on the right side of the screen).

Interior, right arm (on the left side of the screen).

The humanoid central part.

The head, which can revive the arms given time, but is otherwise helpless when alone.

One of Giga Gaia's arms.

One of Giga Gaia's arms.

Several appear on Death Mountain. This is the shell.

The "head" of Mini Lavos, fought on Death Mountain. Kill this to win.

Lavos part imitating the Dragon Tank's Head. Oddly, it has less health than the original.

Lavos part imitating the Dragon Tank's Wheel.

Lavos part imitating the Guard Machine's Bits.

Unused? Looks and acts like the Lavos imitation of the Guard Machine's Bits, but those stats...

Lavos part imitating Junkdragar's legs.

Lavos part imitating Azarla.

Looks like a Primeval Frog. Appears only when the party leader is below level 10. You're highly unlikely to see this form unless you go out of your way to avoid gaining levels on the way there.

Looks like a Marmo. Appears when the party leader is at least level 10, but below level 20.

Looks like a blue Ohgan. Appears when the party leader is at least level 20, but below level 30.

Looks like an Omicron. Appears when the party leader is at least level 30, but below level 40.

Looks like a blue Gran and Leon. Appears when the party leader is at least level 40, but below level 99. Note that physical defense is now normal, while magic defense is elevated. Magic-based (so they hit) combos with a large physical component (to take advantage of his normal defense) are the way to go at this point.

Personally, I recommend Arc Impulse. It's effective, avoids Ayla and Robo (who may very well still have low enough magic defense to be liabilities), and uses a party (Crono + Marle + Frog) that has plenty of healing available.

Looks like a pink Nu. Appears when the party leader has reached the maximum level (99). Even more than before, his defenses call for using magic-based combos with large physical components, as his high magic defense cuts magic damage to about a third as compared to a typical opponent. Frog Flare inflicts more damage than anything else as long as Frog is badly hurt, but otherwise it's little more than an amplified ★Flare, making it mediocre at best. The top reliably effective choices are Gatling Kick, Final Kick, Triple Flame Kick, Glacier Throw, Figa Tackle, Ice Tackle, and Arc Impulse.

Imitating Black Tyranno. Its defenses drop to normal levels when charging flame breath, which occurs after the imitation Azarla is beaten or enough time passes.

Imitating Giga Gaia. Can revive the imitation arms given time, but is otherwise helpless when alone.

Unused shell mode. Has the same stats as Melfikk's core, except for the drastic Water weakness, but does nothing in combat. To speculate, this may have been created at a point during development when Melfikk was simply vulnerable to Water damage directly, instead of the torso and legs losing defense when wet as they do in the final version.

Unused shell mode. Has the same stats as Mother Brain, but does nothing in combat.

Unused shell mode. Has the same stats as Rust Tyranno, but does nothing in combat.

The Abyssal Temple version of the shell, which you're expected to lose against. In addition to having three times the health, this one acts more frequently and inflicts significantly more damage as compared to the usual one.

The normal version of the shell.

Lavos core bit, screen left. Kill it quickly to avoid Seal Protection.

Pun on escargot?

Lavos core bit, screen right. Its defenses drop to normal while preparing to use, or when recoving from using, Life Restoration to revive either or both of the other parts. Kill this part to win.

Killing it with a counter attack avoids the MP Buster dying counter.

Probably Vinnegar's cranks. No sprite. Attacking it triggers an effect that kills all enemies.

In all caps since モンスター would normally be written in katakana. Johnny appears only as an NPC, and you can't fight him without modification, but the enemy is functional if hacked in. 246 exp, 8 TP, 150 G.

It's largely pointless to attack this directly, though in theory, with enough uses of Poyozo Dance...

Son of Sun's flames. One, chosen at random and periodically shuffled, will damage the core when attacked.

Wind Scythe probably isn't worth it, but their formation begs for Whirlslash. Avoid Blaze Wheel because of the resistance.

Magus Castle version. Temporarily loses magic defense when hit with the Grandleon. When hit with anything else, switches to a random elemental vulnerability and uses a spell of that trait. At lower health, his defenses drop to normal levels as he prepares to cast Dark Matter.

Northern Cape version. Though he has higher offensive stats than before, the party's growth should more than overcome that, and his tricks from the earlier battle are absent as well.

Unused. Uses the Magus's sprite, but with the wrong attack animation. Starts using Thundaga, Figa, and Icega as counterattacks when low on health. 10 exp, 1 TP, 100 G.

Presumably a spare. Uses Crono's sprite. Does nothing in combat, but his sword (once it appears after being hit) glows! 10 exp, 1 TP, 100 G.

Presumably a spare. Uses jumbled pieces of Crono's sprite. Does nothing in combat. 10 exp, 1 TP, 100 G.

Presumably a spare. Uses other jumbled pieces of Crono's sprite. Does nothing in combat. 10 exp, 1 TP, 100 G.

Presumably a spare. Uses Crono's sprite, but locks up the game when combat begins.