The Thorn

The Thorn is a 2011 Ninjago weapon that comes in set 2506 Skull Truck.

Lego.com Description:
While this spear might not seem like the most dangerous weapon in Ninjago, you would be foolish to underestimate it. Carved from the tired wood of the yawning Sleepy Willow, this weapon will knock you out… so sweet dreams.