para-eponym
A regular eponym is something named after a person, such as nehru jacket, boycott, volt, bloomer, gerrymander and quisling. A para-eponym is something named after a variation on a person's name, and can be a noun, adjective or verb.
Two para-eponyms are Count Chocula (from Count Dracula) cereal and Cherry Garcia (from Jerry Garcia, a musician favorite of Ben and Jerry) ice cream.