He will tell you of a problem his tipsy tribe has with Sharptooth.
Make sure you aren't carrying too much when you talk to him.
He will give you a big bell, and two jugs of potent plachta.
Use the plachta on a spear to make the special spear of Shamap.
Hunt in the forest across the river, south-east of the village.
When you find Sharptooth, save your game, and use the spear of Shamap.