sorry if it's a bother but I can't find too much on doe/stag/tomcat anywhere so I just wanted to ask how it is racist? is it because of the fact that they're animals or is there something more?
you're fine!! but yeah, that's pretty much it. not necessarily that they're animal terms (although there are many types of animals that have racist associations that at this point it's rightfully generalized) but the fact that they're deer terms in particular. "stag" iirc is eerily close to "buck" which is incredibly offensive to Black people and paints them as aggressive; what a coincidence that the former is a direct indication of masculinity. afaik tomcat has no such connotation but it does get grouped in with the other two so there's that.
you're still free to use them if you want, regardless of race. but it would be insensitive to not at least be critical of the terms (unless you just aren't aware yet).