The trick lets you change species entirely, so he could use it to be a catperson like Q'uila and Felih. I used it to be a bunny Pogemon, so I don't know if Iggy would end up being that specific kind of Pogemon? I think it goes by how you'd look if you were that species. But since catpeople are a species on their own, he should be able to do that one real easy.
Re: no psychic protection
The trick lets you change species entirely, so he could use it to be a catperson like Q'uila and Felih. I used it to be a bunny Pogemon, so I don't know if Iggy would end up being that specific kind of Pogemon? I think it goes by how you'd look if you were that species. But since catpeople are a species on their own, he should be able to do that one real easy.