The Simpsons episode "The Old Man and the Key" features which Simpsons family member?
The Old Man and the Key:  In the episode, Grampa Simpson falls in love with Zelda, an old woman who has just moved into the senior home in which Grampa lives. Grampa Simpson:  Voiced by Dan Castellaneta, he is the father of Homer Simpson and the grandfather of Bart, Lisa and Maggie Simpson.
Grampa Simpson