Grimma is one of the younger of the "outside" nomes introduced in Truckers living together with Masklin, Old Torrit, and Granny Morkie. In the start of Truckers she mainly follows the others without showing much of self-initiative. She does not really want to be a leader. Throughout the story she becomes more and more self-confident. Grimma is the intelligent nome in the group and is good at reading books. In Makslin's absence she becomes the leader of the Council of Drivers in Diggers. Like Masklin she did not want to become the leader. She simply did what needed to be done.