B.J. (Dinosaur)

BJ is a 7-year-old yellow male Protoceratops who has been on the show since Season 2 (1993). He is a good friend of Barney's and is the older brother of Baby Bop, whom he frequently calls "Sissy", though on rare occasions, he does call her by name. He is also Riff's cousin and his best friend. His theme song is none other than "BJ's Song".