Introduced in Call of Duty: Ghostsas the spearhead to the next-generation, Riley is a fearsome companion to the Ghosts. First seen during Microsoft's Xbone conference in 2013, he left a powerful impression on viewers, instilling confidence into everyone for the next generation. Modelled after a real-life SEALS dog and fully motion-captured, this dog is perhaps the most graphically impressive canine in the history of gaming itself. Despite the cloud of controversy, one thing remains clear: putting Riley into the game was the "right thing" to do. In-game, Riley is like any other A.I. comrade, just less terrible. To aid the player character, he'll attack nearby enemies, attack hostile on command, take cover, and even flank the enemy. In addition, Riley can be controlled directly via a camera in his collar, allowing him to stealth kill enemies ahead of the front line. Most importantly however, he can single-handedly take out helicopters. That alone gives him a spot on this list.