"Wait, those were brutes? I thought they were Doritos."
Dumdog was genetically engineered and created in an alternate dimension that was never
affected by the Time Lapse. In that dimension, animals that were physically and intelligically
enhanced by antiplasma created a secret city on Earth, and in the process created Dumdog as a
weapon of defense. Before they could finish engineering Dumdog's brain, he was called into combat
in order to save the city.
Acceptance into Hellcat Squadran
Sorry adolif, you need to write a new story for this...
Dumdog's body is almost pure antiplasma. In times of high emotional stress, Dumdog becomes and indestructable juggernaut, where nothing can stop him. Some members of Hellcat Squadran have already found ways to exploit this ability to combat enemies, such as accusing the enemies of stealing Dumdog's doughnuts. Whenever the enemies try to exploit this ability in the same manner, Dumdog refuses to believe it because of his ironic trust in Natalia.
Dumdog in Alternate Universes
So far, only two varients of Dumdog have been discovered through Hellcat Squadran's inter-dimensional affairs. This is most likely because Dumdog was genetically engineered by a race which ceases to exist in most universes.
Amongst the varients of Dumdog are the "original" Dumdog, and Caninestein.
Caninestein is an alternate, super-genius varient of Dumdog with extreme telekinetic powers and virtually no physical stength. Caninestein exists in the Advent-Verse and serves as the primary scientist and engineer for the Defenders.
Members of the Defenders complain that Caninestein is "just as annoying as he was when he was stupid," because he generally likes to mock the intelligence of others, and also tends to redundantly suggest strategic advice to other members when they least need it.
It is unknown as to how Caninestein suddenly gained such a vast intelligence, but from his description of "glowing ruins," it is thought that Forerunner technology is responsible for the phenomena.