Marvel Comics is a comic book publishing house known for creating notable super heroes such as Spider-Man, Iron Man, Captain America, Hulk, Thor, the Avengers, the Guardians of the Galaxy, the X-Men, the Fantastic Four, and Deadpool. Marvel's most well-known villains include the Green Goblin, Red Skull, Loki, Thanos, Ultron, Doctor Doom, and Magneto. Marvel Comics and DC Comics have collaborated on several crossover projects together and also co-founded the intentionally short-lived Amalgam Comics imprint.