Thanks for reporting, I'll look into it.

The issue is not with rats but with the armour mod. Which mod is that chestplate from?

it was from alexsmobs, but i also tested with a gold chestplate with a resourcepack

I can't reproduce this. What is the exact mod and texture pack you are using for that chestplate which has a missing texture? All of alex's mobs armour work.

https://www.curseforge.com/minecraft/texture-packs/nekos-enhanced-tools-and-armor/comments

This works as expected

please can you provide your latest.log