Heavyweight - S3-E5
Other mistake: When Chet is preparing the lasagna, then tells Johnny that he's preparing 'rutabaga delight' especially for him, the green container of parmesan cheese has tape covering the brand name, though it looks like it's the Kraft brand.





Answer: I believe you are speaking of the old man, Mr. Wilson. He's played by J. Pat O'Malley.
Bishop73
Correct, it was J. Pat O'Malley...he also played the grandfather with his grandson when their rocket exploded, and also played "Old Bill" in the episode with Ann Prentiss, where Gage saves the little girl from the burning tree house, and her mother falls in love with him.