Lockjaw is a character appearing in Professor Layton and the Unwound Future. He is a high-ranked member of the Family (though not as high as Bostro). Lockjaw is one of the two members of the Family who appears in the Gilded 7 Casino, Research Facility, and Mobile Fortress. Unknowingly, he helps Layton & Co. by giving them hints on where to find Flora and Clive in the Mobile Fortress. He is seen over a television screen in the elevator room of the Fortress. As he talks with Layton and co. Luke tells him that if he either stayed with Clive or left Clive would punish him. He then later abandons the fortress.
Lockjaw doesn't appear until near the end of the game to give puzzles. He is seen earlier but doesn't do much else. While Layton and Luke are in the Mobile Fortress Lackjaw does give a single puzzle in the elevator room. In order to activate the machine Layton must find all of the pieces and find the combination. This is the puzzle "Password Pieces".