Ever wondered how you can legally drive a car with a child on board into a giant penguin at top speed? You can't, actually, as "Jackass Presents: Bad Grandpa .5" star Johnny Knoxville revealed when he sat down with the target of his latest prank during this exclusive clip from MTV's Mancation Sunday.

In the movie, Knoxville, in the guise of cantankerous old person Irving Zisman, drives his car into a giant promotional penguin with his grandson (Jackson Nicoll) in the passenger seat. Turns out, though: that was a dummy, as Nicoll wasn't allowed to participate in any of the stunts for legal reasons.

This is revealed as Knoxville sits down the target of the prank, who actually picked the dummy out of the car and threw it at Knoxville -- a scene that hasn't, for obvious reasons, been glimpsed until just now.

"I thought you were a f**king perverted old man," the target told Knoxville. "I thought you had kids locked up somewhere."

You can catch way more "Bad Grandpa" when "Jackass Presents: Bad Grandpa .5" premieres on MTV on Sunday, June 15 at Noon, with encore airings at 10 p.m. and Midnight.