Red Skull

Johann Schmidt, a.k.a. Red Skull, is a supervillain in Marvel Comics. He was portrayed by Hugo Weaving.

Personality
Red Skull is the total counterpoint to his arch-enemy Captain America; while Rogers is good and selfless, the Skull is evil and ambitious. He has little patience for failure and is capable to kill his own minions for giving him bad news. He also has a god complex, and despite wearing a normal-looking mask over his skull face, he later eschews it to signal his pride on his own detachment of humanity.

Marvel Cinematic Universe
In Captain America The First Avenger Johann Schmidt is the leader of HYDRA, the science branch of the Nazis. He goes to Norway and gets the Tesseract to power his weapons. When some high-ranking Nazi officers go to oversee his results, they find he has his own plans to take over the world, including Germany, and Schmidt kills them.

When Captain America goes to rescue some HYDRA prisoners, he ends facing Schmidt, who proves to be strong enough to dent Cap's shield. He then reveals his Red Skull face, revealing he was Erskine's first supersoldier experiment. Then he escapes.

As days pass, Captain America thwarts several of Red Skull's operations, culminating on the capture of his right-hand man scientist Arnim Zola, who gives the location of the Skull's main base out of fear. So Captain America finds Red Skull and makes him pay for stealing the Tesseract to use it for his evil plan. The Red Skull takes the Tesseract to a ship from where he plans to bomb the world's capitals, but Cap gets on board and fights him. Red Skull tries to escape with the Tesseract, but it seemingly disintegrates him as he tried to take the fully charged Tesseract with his bare hands.

Red Skull makes a cameo in The Avengers during Captain America's flashback.

The Avengers: Earth's Mightiest Heroes
Near the end of World War Two, Red Skull tries to use a portal to bring Asgardian creatures to Earth, that will be controlled to serve him. His plan is stopped by Captain America and Bucky, but when the heroes try to stop his escape by plane, Red Skull rigs the plane to explode and ejects himself. Bucky dies in the explosion while Captain America falls and is frozen for several years.

Avengers Assemble
Red Skull is present as a major antagonist of the series. He first appears leading HYDRA forces into fighting Captain America. With the help of MODOK, Red Skull manages to capture Captain America and bring him to his HYDRA base in Antarctica. The reason he had captured his own nemesis was because Red Skull was dying from the side effects of the Super-Soldier Serum attempt that was used on him, so he decided to take Captain America's youthful body and leave Cap to die in his aging body. The experiment was a success, and Red Skull (in Captain America's body) subdued Iron Man. After being freed from the machine, Captain America used Red Skull's body to fight him and the HYDRA soldiers until Falcon manages to switch their bodies back. Before escaping with MODOK, Red Skull managed to steal Iron Man's armor as an alternative to his survival. In "The Avengers Initiative, Pt. 2", Red Skull modifies the Iron Man armor to his design, renaming himself as the Iron Skull. He and MODOK use microbots to cause the Avengers members to fight each other as a diversion so that he can blow up the Arc Reactor in Avengers Mansion. Iron Man manages to thwart the plans. When the Avengers use different tactics to take down Red Skull, Red Skull gets away. While on his submarine, Red Skull sends a message to other villains to join his recently-founded group, the Cabal, in order to combat the Avengers (this message was also intercepted by S.H.I.E.L.D.).

Phineas and Ferb: Mission Marvel
The Red Skull appears as the primary antagonist of the summer 2013 Disney/Marvel animated special Phineas and Ferb: Mission Marvel, voiced again by Liam O'Brien. He was first seen leading his fellow villain allies, MODOK, Whiplash, and Venom into fighting several heroes (Iron Man, Spider-Man, Hulk, and Thor) until the heroes were accidently hit by Dr. Heinz Doofenshmirtz's powerful device called the "Power-Draininator" causing them to flee in battle.

At Red Skull's castle MODOK informs the villains where the ray came from, Red Skull recognizes Doofemshmirtz's last name is Drusselstinian as he has a cousin who married one (and exclaims she is dead to him). When Red Skull and his allies learn that his device drains the heroes' powers, they decide to seek him out, believing that his invention can be of good use for their own purposes. With help from Red Skull and the villains with him, Dr. Doofenshmirtz causes "mayhem" in Danville and nearly destroy the Googolplex Mall.

Eventually, Doofenshmirtz reveals that his Power-Draininator was destroyed by his nemesis Agent Perry the Platypus after it drained the powers, much to Red Skull's anger; but Doofenshmritz manages to create a second and improved replica of the device, much to Red Skull's delight. However, upon finally getting hold of the device, Red Skull betrays Doofenshmirtz by imprisonming him in a cage, believing him to have outlived his usefulness. It was then Red Skull reveals his true plans of using the Power-Drainiator to destroy the Tri-State Area, before draining other superheroes of their powers so that he along with other villains can take over the world. Red Skull has MODOK to make several modifications to the Power-Draininator that will allow itself not only to drain any power from heroes, but also matter and living energy. With help from Phineas and Ferb, as well as from Perry, the heroes were able to regain their powers and defeat Red Skull and his villain allies, who are then arrested by S.H.I.E.L.D. and taken into custody.