Zombie Iron Man is a main protagonist in Super Smash Bros. Crossover starting with Season 16 onward. Zombie Iron Man sends an S.O.S. to the Heroes of Legend when Gigadark Bowser invades Pandemonium. Zombie Iron Man plays a more important role in Season 17, where he learns that during the defusing of Gigadark Bowser, Bowser gained Samus Aran's energy absorbing capabilities, Zombie Reed most likely gained Bowser's fire abilities (which couldn't be proven since Zombie Reed was dead), and Samus gained a trace of the zombie plague. In Season 22, Zombie Iron Man becomes a temporary Hero of Legend in order to purify the Dark Heroes of Legend, and later becomes an official member in Season 26 at Mutabrid's suggestion. In Season 29, Zombie Iron Man battles against Fabia Sheen after she forces Zombie Spider-Man to eat some flesh. However, Zombie Iron Man is forced to leave in order to save Zombie Spider-Man from throwing away his redemption. However, Zombie Iron Man is unsuccessful, but is shocked that Zombie Spider-Man still has some morality. Zombie Iron Man then proceeds to find Zombie Reed to make him pay for his betrayal and ridicule of Zombie Spider-Man. Despite being a Hero of Legend and wielding the Power Cosmic, Zombie Iron Man is killed by the zombie Fantastic Four, but manages to kill Zombie Sue and Zombie Torch before his death. In his final moments, Zombie Iron Man tells Zombie Spider-Man that he is the key to peace between the living and the dead, and that no matter what the hunger forces him to do, he is still a hero to the very end. Zombie Iron Man's corpse is later absorbed by Mechtavius Destroyer, who shares his power with Sasuke Uchiha, Yami Bakura, Sakura Haruno, and Fabia Sheen. Zombie Iron Man is later revived in Season 31 when Naruto and Drago cancel out the Grand Finale after going into the past.
Zombie Iron Man's appearance is based off his appearance in Marvel Zombies prior to getting bisected. After becoming a Hero of Legend, the circle on Zombie Iron Man's armor gains a diamond shaped glow, representing the Smash Core fragment he now possesses.
Zombie Iron Man, like his living counterpart, is quite intelligent. In Season 16, Zombie Iron Man becomes agitated at Zombie Wasp after she gets brain damage due to her antics, to the point where he is tempted to kill her. In Season 29, Zombie Iron Man is shown to care about his fellow undead deeply, as he furiously attacked Fabia for causing Zombie Spider-Man's hunger to reactivate, and ultimately sacrificed his life to make Zombie Reed pay for branding Zombie Spider-Man as a traitor.