After inspecting the coin, you figure the eyeball monster must have meaning to it. There are similar looking monsters on Gazer Isle. You should go there and slay a few to see what happens.
Slay gazers on Gazer Isle.
Slay gazers. (in Tenebrous Tangle)
Speak to Gnibliks Shortstacks or return to Bilgeron Cogsworth.
Speak to Gnibliks or return to Bilgeron. (in Tenebrous Tangle)
Quest Rewards above are only the guaranteed XP, faction, and coin rewarded for this quest. Status points and rewards limited by class, race, alignment, etc. are unavailable.