You never know what celebrities are hiding at San Diego Comic-Con, except if you're Jack Black.

TMZ reported that as soon as a man came across another man wearing an Imperial Stormtrooper helmet, he said, "How you doing, Jack?"

Jack Black responds by saying, "No!"

The first man then celebrated his victory by pumping his fist in the air and saying, "Yeah! I was right. I'm the man!"

The whole interaction was caught by TMZ cameras, and he even tried to tell the cameras that he was confusing him for someone else before taking off the helmet.

He also asked the cameraman how he knew it was him.

"I spent $200 on this thing," he said pointing at the helmet. "This is the worst mask ever."

Black didn't try to hide the rest of his body. He wore a T-shirt and jeans, so that was probably one of his mistakes in trying to blend in at the celebrity-heavy event.

"I bought this thing and everyone's like 'Yo, Jack Black!" he said. "Is it my gut?"

The TMZ reporter then tried to ask Black why he thought that the potential 2016 presidential candidates were less popular than Darth Vader.

"Darth Vader is one of the most popular villains in the history of cinema," Black said. "I don't think that's a bad thing necessarily."

Justin Timberlake is one celebrity who was able to go to Comic-Con unnoticed.

In 2011, the singer went to the convention to promote "In Time." On one of the days, he dressed up as Sesame Street's Ernie, notes People. And though people asked to take pictures with him, it was because of the costume he chose.

No one had any idea that it was him except for Esquire journalist Chris Jones, who was dressed as Burt. Jones tried to get Timberlake to take off his costume, but the singer did not want to.

"No way, dude," he said. "You have no idea what it's like. I can sometimes walk around New York if I dress the right way, but that's it."