Grandpa Louie was the late husband of Ethyl Phillips and father of Fran Sinclair on Dinosaurs. First mentioned in "Hurling Day," Louie appears to Ethyl in the afterlife, warning her of the danger of profiting from her brush with death, in "The Last Temptation of Ethyl." He also warned Ethyl to be more appreciative of her life, because if something is unfulfilled, "we have all the afterlife to regret it".
Louie walked funny after the time Fran fell through the roof and landed on top of him while he was cleaning his pipe. They never found the pipe.