Disguising with masks and fancy outfits is not rare when you are at Comic-Con. Even actors can enjoy themselves at this fun event filled with numerous stars and comic book fans. However, one can sometimes be caught off-guard depending on who it is that comes crashing the party.

Fans of Aquaman had a pleasant surprise when Marvel’s Incredible Hulk actor, Mark Ruffalo, snuck into Comic-Com New York to meet Aquaman Jason Momoa while wearing a Grunkle Stan (Disney’s animated series Gravity Falls) mask.

As seen on the video that Momoa posted on his Instagram account, Momoa was quite excited to meet his “biggest” fan. The two were originally posting for a standard picture, until Momoa excitedly asks the other to remove his disguise. Fans cheered when the mask and hat was taken off, revealing Ruffalo under the disguise. The two had a good laugh at the end of the video. Despite belonging to two different franchises, the two actors don’t have any rivalry between them.

Showing on theaters this December 21, Jason Momoa, playing the titular role, top bills Aquaman together with Amber Heard, Patrick Wilson, Willem Dafoe, Nicole Kidman, Ludi Lin and many others.

Read our spotlight coverage of director James Wan’s Aquaman in the November issue. You can also check out the Aquaman’s official trailer below: