Ham Piper was first introduced in Madhouse (page 64). He lives on Park Slope in Brooklyn, but plays at The Ninth Circle and for the homeless in the subway tunnels; he seems to have a soft spot for those who live on the streets.
He is described as a tall, thin, and black, with “unusually pale brown eyes.” His hair is worn in short dreadlocks. Ham has a deep, mellow voice and is somewhat of a ladies man
It’s said that he is, indeed, The Pied Piper of Hamelin; who as a rat-catcher was hired to lure the rats from the town with his magic pipe. After which, when the citizens refused to pay him for his services, he lured the children of the town away in the same manner.
He may or may not be friends with Ishiah, as the two seem to get along well enough. If not friends, the two are at least amiable towards each other.