Disguises not updated?

are the disguises not up to date with the game? Can you not turn a pig into a parrot or a cat into a vex? You can disguise a parrot but not turn something else into one?

Someone who knows if there's a work around for this please help me. I want killer Parrots but I don't want them tamable. I was going to make Vexes into Parrots but you can't seem to turn things into parrots.

If anyone knows a way to disguise a mob into a Vex or Parrot, it would be appreciated. Thank you.