Who is Weed Atman from Vineland and what is their importance?

Weed Atman is a math professor at the College of the Surf and the accidental leader of the People's Republic of Rock and Roll. Atman is framed by Frenesi Gates as an informer and shot by Rex Snuvvle. He becomes a Thanatoid, a not-quite-dead person who moves to Shade Creek, a Thanatoid village near Vineland.