Tarantula's drops tarantula eyes. Collect them and visit Aloysius Starbolt (located at NW spot of Silversky castle). Say “Tarantula Eyes”, “Yes” and he will trade a pair of eyes for 3.000 gold pieces.

Note: You can do this quest as many times as you want

NPCs involved: Aloysius Starbolt

Quest Reward Synopsis: 3.000 Gold Pieces