Joey
Li'l Joey (aka Wart) is found in Holborn Station. He gives you one of your very first optional tasks, finding his prosthetic leg. When you first meet him his name is Joey (or Li'l Joey), but once you recover his lost prosthetic leg he will announce that he is now your squire, and will change his name to Wart.
Li'l Joey is an homage character, a reference to the character Wirt from the original Diablo game. Wirt, or rather Wirt's body was also found in the Diablo II in the ruins of Tristram. Like Li'l Joey when you first meet him, Wirt had a peg leg which you could recover from his corpse in Diablo II. This leg (like Li'l Joey's Prosthetic in HG:L) could be used as a weapon. Wirt's Leg was also important in Diablo II as it was one of the key items used to access the Secret Cow Level.
Joey's short life was spent scavenging the surface of London and its mountainous piles of decayed men.
But to Joey, the world has always been so terrible. To him there is nothing but the madness of today. To him Hell is a mundane Tuesday. For Joey, an excess of magic has made his damned Earth entirely ordinary.