Here's the second half.
A lot of the Don't Starve creatures remind me of the common features of native Alkian naughts. Specifically the hounds and sanity creatures, with their mouth shape and eyes.

I just found out that this particular creature actually has an official name, Mr.Skitters.

Except it's called "blocker_sanity_fx" in the game's files,which is why it took me so dang long to find it's animation files in the game.