The question is simple. For example, in case I was a Katy stan, I wouldn't like to be named a Katy Cat. But what about you? Do you like the name of your stan base?
Monsters/Little Mosnters and Army are great. As for Madonna, there is no stan name - I personally pull for the Medonsters because I like the Nekci show and I think it's a cute joke, but some people get annoyed with it I guess.