List of Marvel Comics characters: O

Blackjack O'Hare is a fictional anthropomorphic hare in Marvel Comics. The character, created by Bill Mantlo and Sal Buscema, first appeared in The Incredible Hulk #271 (May 1982).
Blackjack O'Hare is a mercenary and leader of the Black Bunny Brigade. He was hired by Judson Jakes and Lord Dyvyne to kidnap Lylla, the C.E.O. of Mayhem Mekaniks. He planned on betraying his employers by marrying Lylla and inheriting the company, but was found out. He was rescued by Rocket Raccoon and after a series of incidents that caused him to question his own loyalty, he aided Rocket in defeating the tyrants and left with his new friends to start a new life.
All this appeared to be false when Rocket visited Halfworld and discovered that Blackjack, along with Lylla and Wal Rus, were originally service animals for the mental patients who inhabited the planet. Blackjack married Lylla after Rocket left to ensure the imprisonment of a dangerous criminal. However, this story was retconned as Blackjack later returned as a mercenary and adversary to Rocket and Groot.
A character based on Blackjack O'Hare named Floor appears in Guardians of the Galaxy Vol. 3, voiced by Mikaela Hoover. This version is a white rabbit who was experimented on by the High Evolutionary and possesses genetic and cybernetic enhancements. She is killed by the Evolutionary during a failed attempt to escape his captivity, but reunites with Rocket during a near-death experience that he has.
Oblivion is a cosmic entity associated with the concept of the primordial void that the Marvel Multiverse sprang from and will eventually return to.
Harry Ocelot is an anthropomorphic ocelot and animal version of Harry Osborn.
Oddball is the name of two fictional supervillains appearing in American comic books published by Marvel Comics.
Oddball (Elton Healy) appears in Hawkeye #3–4 (1983), Official Handbook of the Marvel Universe Vol.2 (1986), Captain America #317, 395, 411–414 (1986–1993), Avengers Spotlight #23–25 (1989), Guardians of the Galaxy #28 (1992), Hawkeye: Earth's Mightiest Marksman #1 (1998) and Wolverine Vol.2 #167 (2001). He was created by Mark Gruenwald. The second Oddball (Orville Bock) appears in Union Jack Vol.2 #2 (2006), Official Handbook of the Marvel Universe A–Z Vol.3 (2008) and Dark Reign Files #1 (2009).
Elton Healey was born in Reno, Nevada. Along with his brother Alvin, Elton spent years as a street performer, becoming a master juggler. He also learned how to become a capable street fighter. Using these skills, Elton became the juggling supervillain Oddball, adopting the name because of his loony nature. With Bombshell, Tenpin, Knicknack, and Ringleader, Oddball forms the Death-Throws, a team of supervillain jugglers. In Wolverine (vol. 2), Oddball is killed while participating in the Bloodsport competition in Madripoor.
Orville Bock became the new Oddball and joined the Death-Throws. Oddball joined the rest of the Death-Throws in London after they were hired by R.A.I.D to take part in a terrorist attack on the city. They were subsequently defeated by Union Jack and Sabra.
Oddball is an expert at juggling, pitching, and catching, with superb coordination, and is highly skilled with thrown objects. He normally carries an assortment of weighted balls and ball-shaped throwing weapons. He typically carried ten 3-inch (76 mm) diameter balls filled with various substances: tear gas, super-adhesive, hydrochloric acid, smoke, concentrated sulfur, spent uranium, itching powder, magnesium flare, a powerful impact-activated electromagnet, a powerful impact-activated sired, or other juggling balls with more exotic contents. He also carried marbles used to trip foes. Oddball has extensive experience in street fighting techniques.
Oddball appears in The Amazing Spider-Man and Captain America in Dr. Doom's Revenge!.
Jake Oh is a character appearing in American comic books published by Marvel Comics. The character, created by Greg Pak and Tyler Kirkham, first appeared in Agents of Atlas #1 (August 2006). He is an agent of S.H.I.E.L.D. who is of Korean American descent.
Okkara was a sentient island located in the South Pacific that was the home of the second generation of mutants, until it was split into two separate islands, Krakoa and Arakko.
Two billion years ago, the first generation of mutants belonged to a thriving society known as Threshold, a civilization in which mutants and humans - known as the Enriched and Enshrined, respectively - lived in harmony. Among them was Grove, a mutant who could heal herself through vegetative growth. When the Unbreathing, an anaerobic form of life to whom oxygen was deadly, attacked Threshold, this invasion drove the people of Threshold to develop biological weapons in the form of the sentient bacteria Arkea and Sublime that turned Enriched and Enshrined against one another when they took on minds of their own. Grove was severely injured in battle but was healed by her powers, which changed her humanoid form with small sprouts into a bark-covered tree-like being. She renamed herself Okkara and survived long after Threshold fell, eventually growing into a free-floating island.
When the Celestials arrived on Earth one million years ago to create the Eternals and Deviants, they also created a subdimensional lattice through the structure of the planet (known as the "Machine that is Earth" or the "Great Machine"), using Okkara as a template.
Okkara eventually became the home for the second generation of mutants, led by Apocalypse and Genesis. Annihilation split the island into Krakoa and Arakko with the Twilight Sword, opening a rift to the dimension of Amenth, and Okkara ceased to exist.
Omega is a gigantic humanoid creation of Maximus which draws upon psionic power from the racial hatred of the Inhumans towards the Alpha Primitives, and converts that power into strength.
Later, Ultron betrayed Maximus and placed his computer-mind within an enlarged adamantium head and transplanted it atop Omega's body. In this form, Ultron attacked the Avengers, Fantastic Four, and Inhumans.
Omertà (Paul "Paulie" Provenzano) is a mutant appearing in American comic books published by Marvel Comics. He first appeared during the Eve of Destruction storyline in Uncanny X-Men #392 (March 2001).
After being discharged from the United States Marines, Paulie Provenzano returned home to Brooklyn and attempted to join the Mafia. Discovering he was a mutant, the Mafia rejected him and attempted to kill him, though Paulie easily subdued his attackers. Soon after, Jean Grey recruited Paulie for a mission to Genosha to rescue the rest of the X-Men from Magneto.
Paulie joined Jean's interim X-Men team, often making jokes and flirting with his female teammates. He objected to working with Northstar due to the latter's open homosexuality. During the trip to Genosha, Paulie, and teammate Hector Rendoza received a telepathic 'crash course' on their mutant powers, allowing them better control and understanding. The team arrived in Genosha and battled Magneto. An overconfident Paulie was hurled into the atmosphere, but Northstar managed to rescue him before he suffocated and resuscitated him. Though uneasy about having received "mouth-to-mouth" from Northstar, Paulie thanked his teammate. After the battle, he declined an offer to remain with the team and left the X-Mansion. Paulie was later codenamed Omertà in the X-Men's database.
Omertà was later captured by the Weapon X program and interned at the Neverland concentration camp. His powers were deemed useless for exploitation by the program and he was executed alongside Maggott.
Following the establishment of Krakoa as a mutant nation, Omertà was resurrected. He entered into a relationship with Stinger and had a child with her.
Omertà is virtually invulnerable. His invulnerability protected him from Magneto's attempt to manipulate the iron in his blood, though he could still be lifted into the air. However, with enough force, he can be hurt and made to bleed, as seen when Northstar punched him while travelling at super-speed. Omertà is also superhumanly strong, able to lift roughly one ton with ease.
The One-Above-All was created by Mark Waid and Mike Wieringo and first appeared in Fantastic Four #511. In his few appearances, he took the appearance of Jack Kirby, which may suggest he is the representation of the actual comic-book writers inside the Marvel Multiverse.
The One-Above-All is the sole creator of all existence in the Marvel Multiverse and, possibly, the Omniverse. He is also the supervisor of the Living Tribunal.
The One Below All is the "dark reflection" or evil manifestation of the One-Above-All. Created by Al Ewing and Joe Bennett, he first appeared in The Immortal Hulk #5 in the form of Bruce Banner's father, Brian Banner, his agent. Alluded to as the qlippoth, or "Hulk", of God, the One Below All is a malevolent and destructive force and the source of gamma radiation-based mutations in the Marvel universe.
The One Below All resides in the Below Place, the lowest layer of Hell, which is kept behind a metaphysical 'Green Door'. All gamma mutates can resurrect after death by traveling through the Door.
Oracle is a Shi'ar who is a member of the Shi'ar Imperial Guard. The character, created by writer Chris Claremont and artist Dave Cockrum, first appeared in The Uncanny X-Men #107 (October 1977). Oracle, whose alter-ego is Lady Sybil, has telepathy and can exert control over others' minds. Using this power, she can project stun bolts. She also has psychoscopic awareness, or "Mind-Sight": the ability to expand her consciousness to read the impressions left by events in the fabric of time and matter. Like many original members of the Imperial Guard, Oracle is the analog of a character from DC Comics' Legion of Super-Heroes: in her case Saturn Girl. Oracle is originally romantically linked with fellow Imperial Guardsman Starbolt; she later marries Flashfire, an analog of Lightning Lad, to whom Saturn Girl is romantically linked.
Ororo-Bug is a member of the X-Bugs and a funny animal counterpart of Storm from Spider-Ham's universe.
Orrdon, the Omega Rocket, also known as Orrdon the Living Star, is a fictional character appearing in American comic books published by Marvel Comics.
Orrdon was an Arakkii Omega-level mutant who could propel himself like a rocket, continuously accelerating as he travelled and becoming invulnerable while using his powers. During the civil war on Arakko, Orrdon sided with Genesis and claimed the Seat of Loss on the Great Ring of Arakko. While on his way to confront Sunspot and Nova, Orrdon flew over territory claimed by Isca the Unbeaten, who killed for trespassing.
Ismael "Izzy" Ortega is a fictional character appearing in American comic books published by Marvel Comics. The character was created by David Hine and David Yardin and debuted in the series District X, where he was partnered with the X-Man Bishop.
Ismael Ortega is a New York City police officer that was stationed in Mutant Town along with his partner Gus Kucharsky. After an accident where a mutant woman uses her powers of persuasion to have Gus kill her husband and herself, Izzy gets a new partner: the X-Man Bishop. They have several events to deal with during the series, including: stopping the drug trafficking of a mutant drug called "Toad Juice", trying to intervene in a gang war between rival mob bosses "Filthy" Frankie Zapruder and Daniel "Shaky" Kaufman, discovering and stopping a group of tunnel dwelling mutants (who are not the Morlocks) that are murdering innocents, as well as keeping an eye on Mister M and finding who put a hit out on him. Aside from work, Izzy also has two young children — Chamayra and Esteban — and a wife named Armena who is a mutant. One afternoon Izzy left his gun at home and it was found by his son Esteban. The boy accidentally shot his sister and she would have died if not for the intervention of Mister M, who removed the bullet and sealed the wound. This caused tension in his marriage, and instead of dealing with his problems Izzy ran into the arms of Lara the Illusionist.
Emily Osborn (nee Lyman) is a supporting character in Marvel Comics. The character, created by J. M. DeMatteis and Sal Buscema, first appeared (as a photo) in The Spectacular Spider-Man #180 (September 1991). She was Norman Osborn's wife and Harry Osborn's mother.
Emily was apparently the only person that Norman ever showed love to, but their son's birth had weakened her with her dying sometime after. However, Emily turns up alive, having faked her death and become Normie Osborn and Stanley Osborn's nanny.
The Ultimate Marvel version is renamed Martha Osborn. Martha is killed by the Green Goblin who was actually her husband.
Overtime is a fictional character appearing in American comic books published by Marvel Comics.
Hector Bautista was a Texan who was incarcerated for a murder he didn't commit. Before Bautista could be executed, the Time Gem bound to him and he used its abilities to escape from prison.
Ozymandias is a fictional ancient Egyptian warlord enslaved by Apocalypse.