UPDATE: It's looking more and more likely that Mark Hamill never was in San Diego for Comic-Con, as was reported (and shared on social by Hamill, himself)! The merry prankster appears to have Tweeted all weekend pretending to be in different disguises, then swearing up and down that he actually was at Comic-Con, even as reports claimed he wasn't. What's real? What's a lie? Even Kylo Ren remains confused, but Hamill pinned this Tweet to the top of his feed, so we now believe this might have been a hoax.
From Earlier: Like so many, Mark Hamill spent some time at San Diego Comic-Con over the weekend. However, it's unlikely he got hassled by too many fans. While Hamill apparently walked the floor of SDCC, he did so in a costume that obscured his identity, Still, he didn't just pick any old outfit with a mask. Instead, he dressed up as a screen-ready First Order Stormtrooper. Check it out.
Of course, Mark Hamill has some experience dressing as a Stormtrooper. While this time he wore the armor of a trooper from the new trilogy, he famously put on the armor of a classic Stormtrooper in the original Star Wars: A New Hope, when he was criticized by Princess Leia for being so much shorter than the rest of the soldiers. Hamill makes that joke here as well, though I'm guessing there were Stormtroopers of every shape and size at San Diego Comic-Con over this past weekend, so it's unlikely anybody gave Hamill a second look.
One certainly wonders if the guy in the Instagram post shown shaking the Stormtroopers hand had any idea who it was he had just met.
In addition to just wandering around SDCC, Hamill's post also makes a note of needing to find a rare Star Wars comic and get the autograph of artist Nathan Hamill, something one would think Mark would be able to do at any time given that Nathan is his son. Finally, he goes in search of great nachos, which, if that's a picture of what he found, he was certainly successful.
It's not uncommon for celebrities to go to conventions in costume. Mythbusters Adam Savage is rather famous for doing it, as he often creates an all-new outfit for every major convention he attends and challenges his fans to figure out which costumed character is him. It helps when you have access to the Lucasfilm costume department, as Hamill clearly had help getting this outfit together. It seems it might not be the sort of thing that you can even put on by yourself.
Of course, Mark Hamill had plenty of time to have fun at San Diego Comic-Con, as the event was somewhat lacking in major announcements regarding a little franchise called Star Wars. While production is about to get underway on Star Wars: Episode IX, Disney mostly took the weekend off as no major movie announcements were made. of course, Star Wars has its own major convention, but Celebration won't be back until next April, and certainly, there will be news to announce before then, though whether or not Mark Hamill is part of any of it still remains to be seen.