Butterball

Emery Schaub, aka Butterball, gained complete invulnerability that permanently locks his body in the same state, making him unable to be harmed by conventional means. Excited to become a superhero, he tried naming himself The Boulder but was renamed Butterball by Taskmaster due to his below-average strength, klutziness, and tubby appearance despite boundless stamina. He was dismissed from critical roles but served as a poster boy for superhuman registration and in the Shadow Initiative, often lingering in the background of young hero teams. Note: Feats primarily from Avengers Initiative #13 & 27, with additional from Avengers Academy #24 and Fear Itself: Youth in Revolt #6.

Durability

• Taskmaster states that Butterball cannot be electrocuted, shot, stabbed, poisoned, drowned, suffocated, or harmed in any conventional way, including mental attacks. (source)
• Butterball can run all day and lift lighter weights without getting tired or losing fat. (source)
• Several superhumans beat Butterball while he sleeps, and he does not wake up. (source)
• Energy beams have no effect on Butterball. (source)
• Energy beams again have no effect on Butterball. (source)
• Additional instance where energy beams fail to harm Butterball. (source)
• Another instance where energy beams do nothing to Butterball. (source)
• Energy beams yet again fail to affect Butterball. (source)
• Further resistance to energy beams demonstrated by Butterball. (source)
• Butterball cannot drown, get drunk, or burn. (source)
• Butterball cannot feel anything, even presumably sexual gratification. (source)
• Butterball survives a building collapsing on him. (source)
• A lifeforce-feeding being states it can feed on Butterball forever. (source)

Limitations

• Taskmaster states Butterball is not strong, not fast, and a klutz. (source)
• Telepaths cannot hurt Butterball but can control his mind, as demonstrated later. (source) (Physical and spiritual pain are very different. The creature is both magical and scientific.)
• Butterball is weak, slow, and cannot build muscle. (source)
• The lifeforce-feeding creature’s interaction highlights differences in pain types. (source)