When we first see Grimsley, he interrupts his boss during dinner one wintry evening to report that a baby was left on his doorstep, the only clue to his identity being a license with the name Claus. The Burgermeister has no intentions of taking in a baby, and orders Grimsley to take the infant to the local orphanage ("Orphan Asylum"). Somehow, Grimsley loses the baby, who miraculously ends up in the hands of the Kringle elves, who adopt him as Kris.
Years later, when the Burgermeister trips on a toy duck and outlaws all toys in retaliation, Grimsley proceeds to enforce it without question, confiscating all the toys in town from the weeping children. When Kris almost wins over the Burgermeister with a yo-yo, it is Grimsley who ruins the moment by reminding his boss that he is breaking his own law. From that time on, Grimsley is constantly trying to capture Kris and his friends on the Burgermeister's orders, and finally succeeds by following Jessica to the Kringles' workshop. It may be inferred that after Jessica helps Kris and his friends escape custody with the help of the magic corn and the reindeer, and right under Grimsley's nose, he probably lost his job, as he never appears again after that.
- Like the Burgermeister, Grimsley was voiced by the late Paul Frees. Unlike the Burgermeister, who talks in a pseudo Germanic accent, Grimsley speaks in a more stereotypically "dash-it-all" British accent.
- Like Smee in Peter Pan, Grimsley does not look at all evil, which in a way makes him more sinister as he goes about enforcing the Burgermeister's harsh anti-toy laws in a totally indifferent manner.