Origin
Rico Axelson was equipped with Phage, a symbiote which was separated from Hybrid. He is part of Mercury Team.
Creation
Rico Axelson was created by Zeb Wells and Clayton Crain. He is based partially on fallen Navy SEALS Sniper Matthew Axelson
Major Story Arcs
Rico Axelson debuted in Carnage USA as part of Mercury Team. He uses the symbiote known as Phage as a weapon. It allows him to hit a shot from a mile and a half away. He is sent after Carnage when he abducts the entire town of Doverton, Colorado.
Mercury team was slaughtered by Carnage, and the symbiotes used the dog to transfer themselves to Deadpool. Afterwards, Deadpool has the Hybrid dog go back to the US Government to be utilized by them again.