The large and imperturbable cat who travels with Cleveland Booker aboard his ship in the 32nd century, and whom he insists on describing as a queen.
Grudge is the pet of Cleveland Booker, introduced with him in That Hope Is You, the opening episode of the third season of Star Trek: Discovery. Book explains that she is so named because she is heavy and all his.
She is a big, long-haired cat, portrayed on set mainly by two Maine Coons named Leeu and Durban. She lives aboard Book's courier ship and later on the USS Discovery, where the crew take turns looking after her.
Grudge appears throughout the third, fourth and fifth seasons. She shows little interest in most people, and Book's devotion to her is a running joke, particularly his habit of correcting anyone who calls her merely a cat.