He only appears toward the beginning of the segment. He stops Peter from going off to find the dastardly wolf with a popgun, spanks him, and tells him that if he tries to go after the wolf, he could very well end up getting eaten. To scare Peter further, he makes a wolf's evil fangs from his beard to show his grandson the shadow puppet of the wolf on the wall. Peter turns around and tries to shoot it, but tricking him, he easily grabs his grandson's cap and popgun from him and storms off. However, when Grandpa falls asleep in his chair by the warm fireplace, Peter manages to get back his cap and popgun and sneak outside.
Grandpa is represented in the music by a bassoon.
In the children's book based off the Make Mine Music segment, it is revealed that after Peter returns, having successfully captured the wolf, Peter's grandfather is pleased with him and is glad to see him safe, despite his disobedience. Peter also promises to listen to and never disobey his grandfather again.