Buza's most notable voice role to date has been that of Dr. Hank McCoy/Beast in the X-Men animated series and related video games. He also had a bit part in the live-action X-Men film as a truck driver. Other voice credits include Chief Chirpa on Ewoks, Grandpa on Beyblade, and various roles on Babar and Tales from the Cryptkeeper. For CBC radio, he acted in episodes of the 1980s scifi series Vanishing Point. Later, he was frequently heard on the various Mystery Project series, including Death Downtown (1997 three-parter, as Constable Hunter), Peggy Delaney (2000-2002, regular as Detective Carlos Szabo) and Rue Morgue Redux (2003 two-parter, Cpl. Larsen) and guest parts on Midnight Cab (with Howard Jerome) and The Old Guy.
On-camera, Buza was seen on the syndicated series The Adventures of Sinbad (regular co-star as burly brother Doubar) and Honey, I Shrunk the Kids: The Series (as police chief Jake McKenna) and had guest roles on the 1980s versions of Alfred Hitchcock Presents and the The Twilight Zone, Friday the 13th: The Series, Noddy, and La Femme Nikita. Film credits include Cold Creek Manor (with Dennis Quaid), Meatballs III, Men with Brooms (with Leslie Nielsen), and Knockaround Guys (with Seth Green).