Uncle Jack is Tyler, Freddie, Jackie, and Carl's Uncle. He used to be stingy, useless and a bad person, and he ate any worker of his who failed. But now he has come to the good side, and is sorry for all he has done. He now has an orphanage, and is a good Bird.

The New, Uninflated Uncle Jack

Uncle Jack

uncle jack

And, yes, he is still rich. It Is implied that he's a secret wizard, member of the order of the Phoenix, but we'll learn about that later.