Following the death of Bill Hogan, the Avenger known as Irondroid, in a war between the Kree and the Skrull races, Stark Interplanetary deployed another employee to become the new Irondroid to fight alongside the Avengers. Willie March was chosen, the descendent of the former Iron Man replacement Eddie March, and joined the Avengers and fought with them against Michael Korvac.
Irondroid was created by Roy Thomas, Randy and Jean-Marc Lofficier and Dave Hoover and first appeared in What If? #36. He is a legacy character, based on the original Irondroid, also created by Roy Thomas (and artist Ron Wilson) who appeared in What If? #19.
Irondroid was introduced in the Timequake crossover which took place entirely in issues of What If?. Irondroid was one of the 4 "champions" from various realities chosen to help save the Universe from the machinations of the Time-Keepers and Time-Twisters. Although Irondroid was killed in a battle against the forces of Limbo, he was resurrected and sent back to his home reality and continued to serve with the Avengers. The Cosmic Avengers received an Official Handbook of the Marvel Universe entry in Avengers Assemble #1 where some of Irondroid and the team's history was embellished on more by their co-creator Jean-Marc Lofficier.