Jay was seen briefly and for last time in The, where Frylock moves out and invites his "new friends" over to a housewarming party. He shows up for the sole purpose of telling Frylock he's not coming, and to stay far away from his wife, his kids, his house, and his dog.
Jay is just the cartoon version of Jay Edwards, Producer and Director for many ATHF episodes, and is also voiced by him.