In the episode "Berry Scary", when Mac looks for a book to guide him beat a world record he announces some of the books titles that are on the shelf on the shelf. He misses one called "BLOCKHEADS GUIDE TO CGI ANIMATIONS". This is a reference to the fact that FHIM was the first cartoon on Cartoon Network to be made in Macromedia Flash.
Mac has a Nintendo GameCube in his room (seen in the episode "Berry Scary")
Bloo mispronounces Berry's name and quotes the famous Bania line from "Seinfeld", "The best, Jerry, the best!".