“Oh my God, what the f--k?!” That’s what Jake Gyllenhaal yelled during an appearance on Ellen DeGeneres’ talk show after a clown popped out of the side table and scared the bejesus out of him.

“Where’s that guy?” asked the red-faced actor, who had to walk it off. “Bring him back!”

Ellen set up the wickedly hilarious Halloween prank by asking the actor, who was on the show to promote his creepy new film, “Nightcrawler,” about his darker roles in films like “Jarhead” and "Prisoners.”

“I have this belief that if you kind of go into the dark sometimes, it can be illuminating,” he said. “I like those characters 'cause they’re kind of fun to play, but I also think there’s an opportunity for...”

Bam!

The clown jack-in-the-boxes right out of the corner table.

“Has he been in there every show I've come on?” Gyllenhaal wonders in disbelief as the segment ends.