Kurt Wagner is the product of a love affair between two mutants, both with origins that have never fully been explained. His mother was the terrorist Mystique, who at the time was the wife of Baron Christian Wagner, believed to be the father of Nightcrawler for a long time. In truth, his father is the Neyaphem warlord, Azazel, who had a great master plan to impregnate earth women with his children so he could escape the brimstone dimension.
When Nightcrawler was born, the townsfolk were horrified by Mystique' son's demonic appearance and so she threw him into a river, shape-shifted into another form and then claimed that she had killed the son and the mother. Azazel would not allow his son to die, so he saved him and gave him to one of his other lovers (and servant) Margali Szardos to raise. Margali tells a different tale to hide the truth and says that Nightcrawler was discovered by her when she was walking by his house. She discovered his father, Eric Wagner, had died of a heart attack outside and found his mother lying next to him dead. Margali took him in and raised him along with her real children Stefan and Jimaine (later known as Amanda Sefton) at the Bavarian circus. She worked as a fortune teller to hide the truth about her sorcery. Kurt had amazing agility and soon his mutant abilities would manifest. Because of these gifts, he did acrobat shows for the circus audience, while people assumed it was a man in a costume.
When a millionaire circus owner from Texas approached them join his circus, he planned to move the circus to America and demanded that Kurt be in the freak show. Kurt was appalled at this, so he quit the circus and headed to Winzeldorf, Germany. He arrives there to find that his brother Stefan went insane and had been murdering children. Kurt battles him, hoping to stop the atrocity, but accidentally kills Stefan by breaking his neck. He tried to tell Margali about her son but she was not at the circus at the time. The coincidence is that, as children, Stefan had made Kurt swear to kill him if ever he took an innocent life. In turn, the villagers thought Kurt was the demon that killed the children.
Nightcrawler was created by writer Len Wein and artist Dave Cockrum.Cockrum was working for DC comics at the time of his conception, he was originally supposed to be a demon from hell that failed a mission and was banished. He was to be a member of the Legion of Super Heroes. He made his debut in Giant Size X-Men #1 in 1975