O – Marvel Comics

O Obliterator Obadiah Stane Obituary Obsidian The Dark Obsidian Ocelot Ocelot Ocean Occulus Ocult   Odysseu Indigo Oddball Offset Ogabe Ogre Ogun Old Lace Old Red Omar Karindur Omnibus Omerta Omega Sentinel Omega the Unknown Onslaught Onslaught OOze Oort the Living Comet Oog Orrek Orrgo Oracle Orak Oracle Orb Orbit Ord Organizer Oriole Orogo Orphan Osako Outlaw Orphan Maker Osiris Otto Vermis Overkill Overkill Overmind Outcast Outcast Overman Over Rider Over Size Overlord Overknight Ovoids Override Owl Ox Ox Oxford Oxbow Ozana Ozymandias Oya Oshun Orifice Oink Oracle Orchid Optoman Ozone Osprey -- -- -- --       Oak Odin Ogre Ogre Overmaster Omegatron Omega Red Onyxx Omni Brit Onslaught Orka Onyx Ogun Overhawk      Omega Gang Octo Sapien