Fulgencio Joseph "Joe" Pritchett is the son of Jay and Gloria Pritchett. He was born in the episode "Party Crasher". He was born just after midnight on his brother, Manny's birthday. While his first name is Fulgencio, Jay says they will never call him by that name as it was only a way to appease Gloria's mother, and instead call him by his middle name Joseph.
In "Spring-a-Ding-Fling" he began to walk. Lily blames breaking Gloria's phone on him by saying he can walk for her. She luckily got away with it until Joe's shoes magically got on the wrong feet.