Marvel: Crossbones

Crossbones (Brock Rumlow) is a supervillain appearing in American comic books published by Marvel Comics. Created by Mark Gruenwald and Kieron Dwyer, the character first made a cameo appearance in Captain America #359 (October 1989), before he was fully introduced later that month in issue #360 and his name was revealed in issue #362 (November 1989).

In his comic book appearances, Crossbones is depicted as a mercenary who is often employed by other villains such as the Red Skull and Hydra. He serves as one of the most enduring adversaries of Captain America, and even played a part in his assassination in the aftermath of the superhero Civil War. A black-and-white skull mask and an insignia on his chest symbolic of his namesake serve as Crossbones' visual motif.

Crossbones has been adapted in various media incarnations, having been portrayed in live-action by Frank Grillo in the Marvel Cinematic Universe films Captain America: The Winter Soldier (2014), Captain America: Civil War (2016) and Avengers: Endgame (2019). Grillo has also voiced alternate versions of the character in the Disney+ animated series What If...?.