Dusty Hill is the bass player for ZZ Top. He was introduced as Hank Hill's cousin in season 11, episode 5 ("Hank Gets Dusted"), in which Hank is crestfallen that Cotton is giving his Cadillac to Dusty instead of him. Dusty enters the Cadillac into a demolition derby, where it is later destroyed. He and the rest of ZZ Top were known and annoyed by Hank for pranking and harassing him for their reality show. Dusty later apologies for destroying the Cadillac, not knowing Hank had wanted it but was passed over.
Dusty's father must be Cotton's brother, and maybe Hank has an uncle.