Ueuecoyotl: [Aztec Empire/Mexico] The Aztec god of sex and irresponsible gaiety.
Ultra Boy:
Umi-Bozu: [USA] Yokai/water spirit from DC Comics Red Circle.
Uncle Scrooge: [USA] The World's richest duck (Disney).
Undertow: [USA] Ray Bailey, a StormWatch operative (Image/WildStorm).
Unicorn, The: [USA] Character from Jim Krueger's series Foot Soldiers.
U.S.Angel: [USA] Joanie Juniper, First American's sidekick (America's Best Comics (ABC)).