Tatsu's face was modeled after Toshishiro Obata, the actor who played Tatsu in the 1990 TMNT live action film.
April mentions that she purchased a book from 'Ray's Occult Bookstore', the store that Ray Stantz (Dan Aykroyd) owns in Ghostbusters 2 (1989).
The video game Mikey is playing is a reference to John Carpenter's The Thing.