Base: Wildlife.rte crab
Bramble: Spiny bramble crab, tiny damage on contact (AEmitter field of hurt pointed upward)
Bubble: Harmless but cute bubbler crab, makes floaty bubbles that pop after a second or so (Lua'd)
Jumper: Harmless jumper crab, every thirty seconds or so jumps (simple Lua script to add 20 upward vel)
Spitter: Harmless but violent crab that spits little bits of green acid or something at troops, heavy enough to damage grass but nothing more
Cute: Disgustingly cute crab with huge moist eyes, just waiting to be picked up and cuddled by some female teen