So I was doing one of the Scarlet Fortress levels today, and a mewkat popped up inside one of those crystal block pens with a couple regular kats. I was going to lure the kats out and kill them so I could take a clean screenshot, but before I could even break the blocks the kats inside somehow killed the mewkat.
I don't think that's supposed to happen.
Kats don't do any damage to other enemies nor blocks, so the bug was on the mewkat (?)
Maybe mewkats are considered to be on the player side and get targeted, like allied mecha knights.