Cody is an alias for Neal Cassady, the famously intense and unstable central character of Kerouac’s famous earlier novel
On the Road (in which Kerouac called him Dean Moriarty). He only appears briefly in
The Dharma Bums, first briefly at a poetry reading, and then when he asks
Ray Smith to look after his suicidal girlfriend
Rosie Buchanan while he’s at work. Rosie ends up killing herself, which devastates Cody.