10 Huge Differences Between Marvel Movies And The Comics
6. Ultron Was Made By Tony Stark
Apparently, deviating from the source material is something that runs in the family.
The differences between the two versions of Ultron are pretty much night and day. James Spader's character in Age of Ultron is a dry and witty snarker, but Ultron in the comics is an angry homicidal maniac. They may share the same goal, wiping out humanity, but the MCU version does it out of a misguided desire to save the planet, whereas the comic version is motivated purely by hate.
A lot of this is probably due to the two characters having very different fathers. In AoU, Ultron was built by Tony Stark and so inherited his sarcastic attitude and altruistic tendencies. In the comics, he was the creation of Hank Pym, whose mental instability left Ultron with a strong Oedipal Complex. He doesn't just want to kill his father, he wants to destroy everything that he's worked to protect.
Ultron does have a history with Iron Man in the comics though. In one particularly weird story, he used one of Tony's old armours as a new body and tried to start a cult based around Ho Yinsen, the man who helped Tony build his first armour. Then, in an even weirder story, he possessed a super-advanced armour that was bonded to Tony's biology and used it to transform him into a replica of Janet Van Dyne.