What kind of shark has a sharp pointed spear coming out of its head?

The shark you are referring to is the Goblin Shark (Mitsukurina owstoni). This deep-sea shark is known for its unique and distinctive protrusible jaws, which can extend forward to snatch prey. The "spear" you mentioned is actually the shark's elongated snout, which is covered in specialized sensory organs to help it detect and capture prey in the dark depths of the ocean.