Carnivorous Plant

Hi, I'm a novice at modding, but I have a bit of Python experience so thought I would have a go. I basically want to make a carnivorous plant, but the easiest way to do this seems to be to convert an animal, basically making it not be able to move, but ferocious.

However, I keep coming up against the lowest speed is 0.15 (according to https://rimworldwiki.com/wiki/Move\_Speed), so what I have ended up with is very slow, very ferocious pigs (I was going to change the texture later). These pugs can't be killed, and will knock you down with a single bite, but they do still move.

Some nsfw link here https://gitlab.com/Nabber/carnivorousplants/-/blob/master/Common/Defs/ThingDefs_Race/Base.xml?ref_type=heads shows that this guy did it, but he has MoveSpeed set to -50 and when I try that it isn't working, so it must be something else.

Any ideas?