U-Man (real name Meranno) is a Marvel Comics supervillain created by Roy Thomas and Frank Robbins, debuting in The Invaders #3 (November 1975) as a deliberate homage to DC's Aquaman. An Atlantean warrior and scientist consumed by childhood hatred for Namor the Sub-Mariner, he betrays his people by revealing Atlantis's location to Nazi Germany, leading to his banishment for treason. Willingly undergoing Nazi experiments that grant him superhuman size, strength, and durability, he adopts the alias U-Man and wreaks havoc on Allied forces until defeated by the superhero team the Invaders. In the modern Marvel Universe, he appears during the Atlantis Attacks storyline and even reluctantly aids heroes like the Avengers and Alpha Flight to prevent a nuclear holocaust. A particularly dark subplot reveals that U-Man raped the villainess Lady Lotus in retaliation for her mind control, resulting in the birth of their child, Nia Noble. His powers include underwater breathing, indefinite survival on land, and enhanced physical attributes courtesy of Nazi science, alongside formal training in warfare.