Created by writers Robert Kirkman and Andy Kuhn, he first appeared in Marvel Team-Up Vol. 3 #21. He was the primary antagonist in the 2006 Irredeemable Ant-Man series.

Mitch Carson was a high-ranked security agent of S.H.I.E.L.D. He killed his father when he was fifteen years old and many others after that. He had, however, never been caught for any of those crimes and managed to find employment with S.H.I.E.L.D.^[1]

Carson was part of the S.H.I.E.L.D. team that took the Iron Maniac into custody and was held alongside the Life Model Decoy (LMD) of Diamondback.^[2] His body somehow adapted to the sedatives used, and he attacked the agents watching him, then activated the LMD coercing it to help.^[3]

Carson was supposed to become the wearer of the new Ant-Man suit made for S.H.I.E.L.D. by Hank Pym. The Ant-Man suit was thought to be stolen, but it actually taken by accident when Chris McCarthy tried it on. Chris was later killed during Hydra's attack on the Helicarrier, and it was then that Eric O'Grady took the Ant-Man suit for himself.^[4]

Carson was determined to find the suit and bring in whoever stole it.^[5] During his mission to capture the new Ant-Man, he was heavily burned in the face during a fight with him. After that, it did not take long for Carson to find out that the new Ant-Man was actually O'Grady.^[6]

Eventually, Carson used an older Ant-Man suit and managed to confront and capture O'Grady. Instead of bringing O'Grady to justice, however, Carson planned to torture.^[7] Carson confessed his crimes as he planned to kill O'Grady, but Iron Man arrived and intervened. Seeing Carson in the Ant-Man suit while torturing O'Grady, Iron Man fought and defeated him. O'Grady lied and said that Carson killed McCarthy and tried to steal the Ant-Man suit. O'Grady claimed to be on the run from Carson and trying to prevent from getting the Ant-Man suit. Carson was arrested for attempted murder and stealing the Ant-Man suit.^[1]

Mitchell Carson has S.H.I.E.L.D. training, specifically in firearms/explosives, espionage, intelligence gathering, and hand-to-hand combat. He gained access to an old Ant-Man suit which he used to shrink and take out the more advanced Ant-Man suit utilized by Eric O'Grady.

Mitchell Carson appears in Ant-Man (2015), portrayed by Martin Donovan. This version is an agent of Hydra who previously worked undercover as the Head of Defense of S.H.I.E.L.D. during the 1990s and partook in the latter organization's failed attempt at replicating Hank Pym's Pym Particles. In the present, Carson and a group of Hydra agents meet with Darren Cross, Pym's former protégé who had successfully created his own formula and developed the Yellowjacket battlesuit. After Pym, Scott Lang, and Hope van Dyne intervene, Carson absconds with Cross's replicated technology. In an alternate ending, Carson is apprehended before he can escape.

• Mitchell Carson at Marvel Wiki