Mammomax (Maximus Jensen) is a fictional mammoth-shaped human mutant who exists in the Marvel Universe. Mammomax's first appearance was X-Men v2 #161.

When he first appeared, he was part of the Brotherhood of Evil Mutants alongside Avalanche, Sabretooth, Exodus, Juggernaut, Nocturne, and Black Tom Cassidy. He was defeated by Iceman and later sucked into the black hole within Xorn's head, which apparently led to the Mojoverse.

Mammomax next appeared after M-Day on the run from members of the Sapien League with Erg and Peepers. He was rescued from being burned alive at the Institute's front gates by the X-Men. He took up residence on the Institute's grounds with other members of the 198. He also formed a friendship with Erg, Fever Pitch, and Sack. During a recent outing into Salem Center, he attacked a boy for calling him "Elephant Man", but a "tracking chip", implanted in his head by The Office of National Emergency (O*N*E), disabled him before he could hurt the boy. Mammomax had the device removed by Mister M along with all the other members of the 198. He also followed Mr. M during his exodus from the Xavier Institute.

Mammomax looks like a bipedal elephant with hands, because of this he is as strong as an elephant and also possess a pair of large ivory tusks which are as durable as an elephant's. Mammomax has invulnerable skin and can also produce powerful stomach acid which he can spit out of his mouth and use as a projectile attack.

{{cleanup-remainder|November 2006 One of the writers of the new handbooks e-mailed this to me personally concerning his real name,which was revealed in Wizard magazine #181

We've checked with Marvel, and it is new but officially sanctioned information given to Wizard, so yes, it is accurate.