I would say that the stupidest animal name is the “small-eyed big-eyed hunting spider”, but there’s another related spider called the “no-eyed big-eyed spider”. I’m not sure which is a sillier name.
For your consideration: the burrito grunt.
Fish in the family Haemulidae have a lot of my favorites. Harry hotlips (Plectorhinchus gibbosus) is great because it’s just a fun drag king name. Also in that family are the blue bastard, biglip grunt, Panama porkfish, and the Cock grunter