Jared Leto wore a disguise to hang out with cosplaying Jokers at Comic Con and they had no idea it was him
Mark Ruffalo wasn't the only celebrity who headed to New York Comic Con in disguise.
Academy Award winner Jared Leto, who will be playing the Joker in next year's "Suicide Squad," also took to the Javits Center during the four-day event from October 8-11 wearing a baboon mask, and no one had any idea.
Here's another look from Leto's Snapchat:
Leto was in for a treat because two of the most popular outfits of the weekend were of his upcoming Joker and the character's partner in crime, Harley Quinn.
Fans were inspired by the first trailer for "Suicide Squad," which debuted in July. New York Comic Con was one of the first big opportunities for people to show off any cosplay for the upcoming movie.
The 43-year-old actor went around snapping images of unsuspecting Jokers, Harleys, and other "Batman" characters. Here are some of his Snaps:
This Comic Con attendee would have flipped out if she knew the real Joker was right in front of her.
After it was all over, Leto let everyone know that he went completely undetected.
Ruffalo and Leto aren't the first celebrities to head to Comic Con undetected.
In 2013, Hugh Jackman said he dressed up in his full Wolverine costume for San Diego Comic-Con and no one stopped him. That same year, Bryan Cranston walked the floor as his "Breaking Bad" character.
"The Lord of the Rings" director Peter Jackson and Daniel Radcliffe have all disguised themselves, too, to find out what it's like to walk around these giant fan conventions.
Often, it's because they want to experience the conventions just like the fans do.
Radcliffe said he dressed as Spider-Man to his first San Diego Comic-Con so he could explore the showroom floor on his own without the worry of causing a big commotion.
"You don't go to Comic-Con without going down on the floor and seeing it all," he told MTV.
He said he even was able to take photos with unsuspecting fans.
"Doctor Who" actor Matt Smith wore a Bart Simpson mask in 2013 to chat with fans, compliment cosplayers, and to check out the floor.
Other times, celebs at the Con just want a chance to buy something.
Actor Jack Black tried and failed last year to disguise himself as a Stormtrooper when he took his helmet off before heading into a panel for "Goosebumps."
The actor said he simply wanted to "buy some things at Comic-Con."
He was able to get his hands on a figurine of his favorite character, the Red Hulk, before the crowd caught on.