Swap Enemy Models

[SpeedyDoggo]

Hello! I'm looking for a way to swap out one type of enemy model with another. I tried opening a blank mod in Penumbra and using the advanced editing -> file swaps using enemy models/textures imported from the screen. The target enemy hasn't changed so I'm not sure how to parse what's going wrong.

(I'm not trying to swap spiders out so any pre-existing arachnophobia mods won't work for my purposes, though admittedly I haven't found any of those either.)

Thank you for any help! I was hoping I could do this natively in Penumbra but I'm really not sure how.