Calvin's maternal grandmother is mentioned after Calvin misbehaved in the doctor's office, when his mother tells Calvin, "Someday I hope you have a kid who puts you through what I have gone through.", to which Calvin replies, "Yeah, Grandma says that's what she used to tell you." She is also mentioned when Calvin's mom is typing on a typewriter. Mom: "Who wrote 'Help I'm a bug' on my letter to Grandma?" (though it's possible she was talking about her own grandmother). In another strip, Calvin is writing a thank-you note to Grandma for sending him a box of crayons as a gift. Hobbes comments on the quickness of the note, and Calvin says "Yeah, I always write her a thank-you note right away...Ever since she sent me that empty box with the sarcastic note saying she was just checking to see if the postal service was still working." Also, in another strip, Calvin comments "Wait till mom sends my picture to Grandma!" after Hobbies styled his hair and before he made a funny expression on one of his school pictures.