Ah, Thanos. Such a polarizing character in the Marvel universe. As the super baddie in Avengers: Infinity War, Thanos pissed off a ton of viewers with all the people he killed (don't worry, I won't spoil it for you), which naturally means he's a popular costume choice this year. He's not new to comic-book fans, but his huge role in this year's Avengers movie put him in the spotlight and made him the inspiration for cosplayers everywhere.
At Comic-Con this year, people showed up with makeup looks that were so realistic, you would have sworn they'd walked right off a movie set. Other people have drawn inspiration from Thanos and his quest for the Infinity Stones for more delicate makeup looks with subtle pops of color and gems attached to their bodies. No matter how you swing it, you too can be everyone's favorite Marvel villain using one of these makeup creations as your inspiration.