WATCH: Henry Cavill Goes Undercover to Prank Will Smith at Comic-Con

Henry Cavill pranked Will Smith at this year’s Comic-Con — and his reaction was priceless.

The Batman v Superman: Dawn of Justice star got into the Comic-Con spirit over the weekend in San Deigo, Calif., rocking a Guy Fawkes V for Vendetta mask to explore the convention floor without being mobbed by fans. However, that’s not the main reason why he sported the costume.

Cavill went undercover as he waited in line to get an autograph from Smith, who was promoting his film, Suicide Squad. He posed for a photo with the actor, who had no idea he was someone other than a normal fan, and later pulled off the mask to reveal his true identity. Luckily for us, Cavill documented the whole thing and shared the video on his Instagram.

In it, we see the whole cast’s reaction to Superman — including Viola Davis, Scott Eastwood, Jared Leto. The Suicide Squad members even signed his T-shirt.