Rowley's grandfather

Rowley's Grandfather is the father of Robert Jefferson, father-in-law of Mrs. Jefferson and the grandfather of Rowley Jefferson. So far, he has only made an appearance in Rodrick Rules, and has made no further appearance. He has only been seen in the series when celebrating his birthday, in which Greg mocked him over what birthday cake he would prefer next year. Like Rowley's parents, he dislikes Greg.

Trivia

 * He is most likely deceased, since he has not been shown or mentioned after Rodrick Rules.