Wolverine is a fictional character appearing in American comic books published by Marvel Comics, often in association with the X-Men. He is a mutant with animal-keen senses, enhanced physical capabilities, a powerful regenerative ability known as a healing factor, a skeleton reinforced with the unbreakable fictional metal adamantium, significantly delayed aging and a prolonged lifespan and three retractable claws in each hand. In addition to the X-Men, Wolverine has been depicted as a member of X-Force, Alpha Flight, the Fantastic Four and the Avengers. The common depiction of Wolverine is multifaceted; he is portrayed at once as a gruff loner, susceptible to animalistic "berserker rages" despite his best efforts, while simultaneously being an incredibly knowledgeable and intelligent polyglot, strategist, and martial artist, partially due to his extended lifespan and expansive lived experiences. He has been featured in comic books, films, animation, and video games.