The Lion's Bow is a crossbow used by the villain called Terrat. This bow has the ability to shoot multiple elements, including an arrow with a lion's tooth. The arrow can shoot multiple directions, and could follow an opponent within it's range.
The lion's bow is actually a Hero Factory design for Dr. Aldous Witch. However Terrat was able to capture this weapon before being sent to prison. It is built with a claw that the Witch Doctor has on his gun. The arrow itself can trigger a chain reaction, though different elemental powered arrow's cause different reactions.
Terrat himself is not a smart villain as he does not know how to launch an arrow correctly. Beware, because no matter where you run, it follows you. It is Terrat's major weapon but the Meteor Tank Arm is more commonly used for defense.