Annihilus was an alien from the N-Zone and leader of his race.
Annihilus was the ruler of his race, and noticed a portal that opened and a spaceship that went through it and back. Seeing this as an opportunity to escape their dead reality, Annihilus used his Cosmic Control Rod to hit them with a cosmic storm. They escaped, but he knew they would come back for their dead friend. Once they came back, Annihilus captured them and questioned if there were more humans on the other side of the "door". When this was confirmed, he rallied his forces to attack the world, but was thwarted by the captives. He was killed in the ensuing battle.
Super strength and durability. Could fly thanks to wings. Had the Cosmic control rod and could control the very cosmos.