Adamantium is a fictional metal
alloy appearing in
American comic books published by
Marvel Comics, and is best known as the substance bonded to the character
Wolverine's skeleton and claws. Adamantium was created by writer
Roy Thomas and artists
Barry Windsor-Smith and
Syd Shores in Marvel Comics'
Avengers #66 (July 1969), which presents the substance as part of the character
Ultron's outer shell. In the stories where it appears, the defining quality of adamantium is its practical indestructibility.