Lion tamarins could be SKITTISH? They're small and have a lot of predators.
Same with pangolins: SKITTISH.
Moray eels currently don't attack you if you hit them. Make them PROVOKED or AGGRESSIVE? They can be pretty nasty in real life if you sneak up on them.
Okapi are shy and might be a good option for SKITTISH.
Giraffes tend to run from predators and strange things, so maybe SKITTISH for them too?
Fish stuff:
Salmon can be bred with seeds. Why not all the other fish? Especially cichlids, which are a good exhibit filler and I want an army of them.
Three cichlid variants have textures on the drive but are not implemented.
Slightly slower swimming for all fish mobs? All the non-tameable fish, plus the eel, move very, very fast
Rats
Rats are tameable, but maybe have wild rats breedable with an item so they can be farmed for snake chow.
More aggression updates:
Fish stuff:
Rats