Introducing: Anything!

Who is "Anything"?   It's a superhero that Brennan invented. Anything has a mix of all kinds of super powers and doesn't always wear the same costume.  Since he's "Anything," he can do anything, wear anything, be anything.  Brennan keeps telling me he wants to have an "Anything" themed birthday party.  When I suggest a superhero party, he keeps saying, no an "Anything" party.  I'm going to have to figure out how to navigate this one!