Walter is at least 200 years old, and has experienced conflict in numerous wars. He was in Shanghai during the Opium War, in Balaclava during the Crimean War, in Delhi during the Sepoy Mutiny, in Passchendaele during World War I, and in El Alamein during World War II, during which he served with military intelligence. In 1944 his station was attacked by the Nazis with a large robotic war machine. The war machine was confronted by the Invaders (Captain America, the Submariner and the Human Torch), but rendered them unconscious. Walter then transformed and destroyed the robot before fleeing from Allied soldiers, who happened on the scene and thought him in league with the Nazis. As part of the Relative Stranger Protocol, he is known today to outsiders as the son of the Walter Destine who served in WWII. He is the guardian of Rory and Pandora, who were led to believe for years that he was their uncle. They gave him the codename Wallop, though he refuses to accept this name. As the twins' primary guardian, he is generally strict, and resents the appearance of the other siblings in the children's lives when it suits them, especially Kay, who he feels tries to buy the twins' affections with gifts when her hedonistic lifestyle allows. Alan Davis tried to design a costume for Wallop, but felt they all looked silly in some of his more extreme incarnations.