Lou Pickles is one of the prominent supporting characters in the Rugratsseries whom has been in the series since right from the start. Grandpa Lou is the beloved grandfather of Tommy, Dil and Angelica Pickles (and is the father of Stu and Drew Pickles) and he is quite the consummate "young at heart" old man. Ol' Grandpa Lou would gladly tell stories about hist past just about any chance he gets (in which he often uses the number 15 in various ways) but despite his adventurous personality he does have plenty of health problems such as achy bones and is frequently asleep when he is suppose to be watching the kids. For an unknown amount of years Lou was a widower and he does love his late first wife (though he doesn't seem to have any issues over that) but over the course of the franchise he has a 2nd wife named Lulu in which they love each-other very much.
David Doyle voiced Lou Pickles for the first few seasons. Following his death, Joe Alaskey took over the role.