Ultron () is a fictional supervillain appearing in American comic books published by Marvel Comics. The character was created by writer Roy Thomas and artist John Buscema, and initially made his debut as an unnamed character in The Avengers #54 (1968), with his first full appearance in The Avengers #55 (1968). He is a self-aware and highly intelligent robot created by Hank Pym, who develops a god complex and a grudge against Pym and the human race. Ultron's goal to destroy humanity has brought him into repeated conflict with the Avengers. Ultron's physical body is made of a durable alloy, and he has manifested various superpowers. These vary between different stories but generally include superhuman strength, speed, and agility, flight, and energy projection. The character usually operates alone or accompanied by legions of copies of his own robotic form known as Ultron Sentries. However, Ultron has also been part of several supervillain teams. Ultron is notable for being the first character in Marvel Comics to wield the fictional metal alloy adamantium and for his (in-story) creation of the character Vision. Debuting in the Silver Age of Comic Books, Ultron has since featured in Marvel products across different media, such as animated television series and video games. Tom Kane and Jim Meskimen are among the actors that have portrayed the character through voice acting.