Red Skull (Marvel Cinematic Universe)

Johann Schmidt AKA the Red Skull, is an antagonist in the MCU. He appears as the main antagonist of Captain America: The First Avenger and as a cameo in Captain America: The Winter Soldier. He is also briefly mentioned in Marvel's Agents of SHIELD. Red Skull was the leader of HYDRA during the Second World War.

Captain America: The First Avenger
Red Skull is the main antagonist of the film. In this adaption, Schmidt forces dr. Abraham Erskine to use his Super Soldier Serum on him. The unfinished serum caused a side-effect that left him deformed, forcing the Skull to wear a rubber mask of his former self. At the beginning of the movie, Red Skull travels to Norway, to obtain the Tesseract. Using its powers, Arnim Zola develops advanced weapons, that Skull believes will aid in winning the World War. Several high-ranking SS officers come to check upon his plan, Schmidt intends to bomb every major capital on Earth, including Berlin. This rages the officers and Schmidt kills them in order to break free from the Nazi Party. In the meantime, dr. Erskine uses his finished serum on Steve Rogers, who becomes Captain America, but not before that Heinz Kruger, an udercover assassin kills Erskine. Captain begins to take down HYDRA bases, with Skull finally retreating to his last base in the Swiss Alps. He begins his plan and flies the Valkyrie, his Tesseract powered plane into bombing the United States. Rogers infiltrates the plane and starts a one-on-one battle with Schmidt. Schmidt touches the Tesseract and disintegrates, leaving his ultimate fate unknown.

Marvel's Agents of Shield
Schmidt is mentioned several times by Daniel Whitehall, the series' incarnation of Commander Kraken.

Trivia

 * Red Skull is the only villain in the MCU, whose fate is unknown.
 * He is portrayed by Hugo Weaving, who also portrayed Agent Smith in the Matrix films and Megatron in the Transformers film series.