Cthulhu Demonbane OBD
Cthulhu bursting through from the Black Lodge's HQ, Illusionary Heart Mother.

Name: Cthulhu, The Great C
Origin: Demonbane
Gender: Referred as a male, otherwise N/A
Classification: Evil God, Great Old One, The Ruler of R'lyeh
Age: Billions of years
Powers and Abilities: Super speed, strength, durability, endurance, immortality (types 1,3 and 4), regeneration (High-Mid), magic, reality warping (can turn the entire Earth into a world of demons), energy blasts, energy absorption, weather manipulation, water manipulation, teleportation, soul manipulation, mind manipulation, telepathy, telekinesis, barriers, can summon thousands of minor gods equal to Dagon in power, can be sacrificed in a ritual to summon Yog Sothoth
Destructive Capacity: Country level with the combined salvo of its tentacles (destroyed the entire Arkham City which has about 100 sectors, each with the size of a small city), life wiper via its miasma or merely the re-surfacing of R'lyeh, potentially planet level in its true form (Great Old Ones at Cthulhu's level were claimed to be planetbusters)
Range: Dozens of kilometers with its tentacles, planetary with magic
Speed: Unknown, massively hypersonic+ attack speed/reactions
Durability: At least island level+, regeneration makes it rather difficult to kill
Lifting Strength: Class T due to its size, Class E via telekinesis (can rise the city of R'lyeh which is the size of a small continent)
Striking Strength: Unknown, Class GJ+ for each individual tentacle (can chomp Dagon apart with ease)
Stamina: Virtually limitless
Standard Equipment: Billions of tentacle heads (each with mouths at least as large as Demonbane), at least many thousands of flying Destroyer Robots, thousands of minor gods comparable to Dagon, countless Deep Ones (capable of taking down submarines in groups)
Intelligence: Mindless due to being under the Black Lodge's control.
Notable Attacks/Techniques:

Notable OBD Victories:

Notable OBD Losses:

Other: Many if not all of Cthulhu's feats come from the time it was sealed within the Illusionary Heart Mother. Cthulhu at full power was implied to be far stronger than that. Not to be confused with his original Cthulhu Mythos counterpart.