When the Griffins are put on TV, who plays Peter on "Family Guy"?

When the Griffins are put on television in “Family Guy,” Tom Arnold plays Peter Griffin. The joke comes from the show’s recurring habit of turning the Griffin family’s life into a fictional broadcast, allowing a real celebrity to portray or stand in for one of its animated characters.

Tom Arnold appears as himself in the television-related storyline, while Peter’s usual voice is performed by series creator Seth MacFarlane. Arnold’s casting is therefore a gag within the story rather than a change to the regular voice cast or the permanent identity of Peter’s performer.

This distinction causes the most common confusion: Seth MacFarlane remains Peter Griffin’s standard voice, but Tom Arnold is the answer to the specific in-show question about who plays Peter when the Griffins are put on TV. “Family Guy” frequently uses celebrity cameos and alternate portrayals to parody television production and media culture.