- "What? How are we even breathing?"
"An excellent question, but not even remotely the point."
- ― Kevin Levin and Professor Paradox (Ben 10: Alien Force)
The power to survive without oxygen.
- Anaerobic Respiration
- Doesn't Breathe
The user has no need for oxygen, allowing them to survive indefinitely in airless environments. Because of this, they can simulate powers such as Atmospheric Adaptation, Aquatic Breathing and Vacuum Adaptation.
In some cases, the user simply does not have to breathe.
- Despite being able to survive without Oxygen, the user is still vulnerable to environments filled with air-borne hazards.
- Users may be Oxygen Intolerant.
As a vampire, Angel (Buffy the Vampire Slayer) has no need to breathe, allowing him to survive being trapped at the bottom of the ocean for three months...
...and in a demon dimension with an atmosphere toxic to humans.
Cain Marko/Juggernaut (Marvel Comics)
Being made of air, Wind Fables (Fables) do not need to breathe. Because of this they are able to be underwater without any ill effects.
All Ice Elementals (Serious Sam) have no requirement for oxygen due to their inorganic nature.
Water Elementals (Serious Sam) have no need for oxygen due to their inorganic physiology.
Gems (Steven Universe) possess gem-stones that project humanoid forms out of light. Because of this, they do not need to breathe.
Like all Kryptonians, Power Girl (DC Comics) can survive without oxygen as long as she is empowered by the radiation of yellow or blue stars.
As they are technically undead, the Fork Maidens (New Blood Interactive's DUSK) have no need for oxygen.
Due to being inorganic beings, the Possessed Scarecrows (New Blood Interactive's DUSK) have no need for breathing oxygen.
The Turrets (New Blood Interactive's DUSK) have no need for oxygen due to being mechanical sentries
Being undead, Owen Harper (Torchwood) has no need for oxygen, allowing him to survive underwater.
SCP-030 - The Homunculus (SCP Foundation) is oxygen-independent thanks to its physiology as a Homunculus
As a result of adapting to the low air pressures on a high mountain range SCP-096 - The "Shy Guy" (SCP Foundation) has no need to sustain himself with oxygen.
Jason Voorhees (Friday the 13th)
As an extraterrestrial creature, King Ghidorah (MonsterVerse) likely doesn't need to breathe in order to survive, making the Oxygen Destroyer that destroys natural lifeforms useless against him.
Destoroyah (Godzilla series)
As a Slime, Rimuru Tempest (That Time I Got Reincarnated As A Slime) doesn't need to breathe because of his body operating on magicules.
Frieza (Dragon Ball Series)
SCP-030 - The Homunculus (SCP Orientation)