The Room actor, 9, is making a foul-mouthed guest appearance on The Last Man on Earth, and PEOPLE has exclusive video of his handiwork.
Jacob plays the kid version of Phil/Tandy (Will Forte), who appears to Mike Miller (Jason Sudeikis) in a haze after his space capsule lands on Earth. Mike believes that he is the last man on Earth, but little does he know, his big brother Phil is still alive.
Young Phil and Mike immediately engage in some brotherly bickering, with Jacob giving his onscreen brother plenty of insults, including "stupid," "freakin' turd" and "fart face" – and also telling him to "shut your butt."
Classic stuff, Jacob. Classic stuff.
Last Man on Earth returns Sunday (9:30 p.m. ET) on Fox.