Crossbones is a super villain under the American Marvel Comics. His original name is Brock Rumlow. He was jointly created by Mark Grunwald and Kieron Dwyer. First appearing in the 359th issue of "Captain America" ??(October 1989), he is Captain America's old enemy - the most loyal subordinate of the Red Skull. He has been loyal to him for many years. He is a member of Hydra and a world-class mercenary. . Crossbones was played by Frank Grillo in the Marvel Cinematic Universe's 2014 "Captain America: Civil War," and in the 2016 movie "Captain America: Civil War," Frank Grillo continued to play Crossbones.