The mechanical shark used in the movie Jaws was nicknamed...

Answer: D - Bruce.

This was the name of Stephen Spielberg's lawyer.

During pre-production, director Steven Spielberg, accompanied by friends Martin Scorsese, George Lucas and John Milius, visited the effects shop where "Bruce" the shark was being constructed. Lucas stuck his head in the shark's mouth to see how it worked and, as a joke, Milius and Spielberg sneaked to the controls and made the jaw clamp shut on Lucas' head.

Unfortunately, and rather prophetically, considering the later technical difficulties the production would suffer, the shark malfunctioned, and Lucas got stuck in the mouth of the shark. When Spielberg and Milius were finally able to free him, the three men ran out of the workshop, afraid they'd done major damage to the creature.