In the animated series “Family Guy”, which character is not voiced by the creator Seth MacFarlane ?

Cleveland Orenthal Brown Sr. is a fictional character from the animated television series Family Guy, and its spin-off series The Cleveland Show and he is voiced by Mike Henry while Seth MacFarlane voices three of the show's main characters: Peter Griffin, Brian Griffin, and Stewie Griffin. MacFarlane chose to voice these characters himself, believing it would be easier to portray the voices he had already envisioned than for someone else to attempt it. MacFarlane drew inspiration for the voice of Peter from a security guard he overheard talking while attending the Rhode Island School of Design. Stewie's voice was based on the voice of English actor Rex Harrison, especially his performance in the 1964 musical drama film My Fair Lady. MacFarlane uses his own voice while portraying Brian.

MacFarlane also provides the voices for various other recurring and one-time only characters, most prominently those of neighbour Glenn Quagmire, news anchor Tom Tucker, Lois' father Carter Pewterschmidt and Dr. Hartman. He explained on the Graham Norton Show that the voice for Glenn Quagmire is based on 1940s and 1950s radio commercials. He is the only cast member to be in every episode.