In the YouTube channel of dudaw12 we can see a video of Mario 64 “hacked”, where there are some little Chill Bullies that are not used in the final game.
As hes say in the description of the video “Using Toad’s Tool 64 by VL-Tone, I added the model ID of mini Chilly Bullies in Super Mario 64. Perhaps they were beta elements? Or maybe just a scaled model left in the game? I don’t know.” If you dont remember who Chill Bully is, here’s a description from Mariowiki:
“Chill Bully is a Big Bully found in Super Mario 64. It has a blue surface and a single golden spike on the top of its head (as opposed to the usual black surface and twin horns of normal Bullies). Chill Bully appeared in Course 10: Snowman’s Land. In this level, Chill Bully walked around on an ice platform above a pool of extremely cold water.” In M64 Chill Bully is just one big boss, but these little ones could have been “ordinary” harder enemies for the same level or maybe from a removed one?