Onslaught is a fictional character that appears in comic books published by Marvel Comics. The character first appeared in cameo X-Man #15 (May 1996), his first full appearance in X-Men vol. 2, #53 (June 1996). Onslaught was co-created by writers Scott Lobdell, Mark Waid, and artist Andy Kubert. He was written and introduced as a villain that was part of the effect of events in the 1993 Fatal Attraction storyline.