10greys wrote: I wonder who he was. Don't think he was ever mentioned.
I think the only reference to the man was made by Sokka in the episode "The King of Omashu" before anyone had met Pakku. When Aang tried to disguise himself as an old man to sneak into the city, Sokka made the comment that "[Aang] looks like my grandpa."
I just re-watched that episode last week, and I thought it was strange that they (Sokka and Katara) never mention their grandfather after this considering how much the refer to their grandmother throughout the series.