Meet Rocko Akira Clapp.

He's the son of Jackass star Johnny Knoxville (real name: Philip John Clapp) and girlfriend Naomi Nelson.

On Saturday, Knoxville, 39, stepped out for the first time with the boy in Malibu, Calif. (Weighing 8 lbs., little Rocko was born last December.)  

Before his new son's arrival, Knoxville blogged, "My daughter Madison [mom is ex-wife Melanie Clapp] has already started becoming a big sister too and is helping pick out clothes, strollers and beds for her new little sister or brother."