When Steve has the pillow fight with Marty, you can see his dad's shadow and a bit of shirt and pants by the door, waiting for his que.
Marty: Do you like Yasmine Bleech?
Grandpa: Yah. I love havin' teeth.
Jerry Van Dyke was last seen in the episode "One Dog Night" as a guest star in this series..
Jerry Van Dyke joins the main cast as Grandpa Max in this episode.