Clacker

Clacker was a hook horror who lived in the Underdark.

Background
Clacker was originally a pech, a member of a species that has a special bond with the earth. However, after an encounter with a human wizard named Brister Fendlestick in his Underdark home, Clacker was turned into a hook horror. Under the effects of this spell, the lone pech forgot his name, much of his past, and began to lose everything about him that remained pech as his mind began to transform.

History
Clacker received his name and comfort in his exile when he met the drow Drizzt Do'Urden and the Svirfneblin Belwar Dissengulp. The two befriended Clacker and tried to help him escape his torture by convincing the wizard to return him to normal. However, in a fit of blind rage invoked by the wizard's contempt of his people, Clacker killed the human.

Clacker joined Drizzt and Belwar as they journeyed through the Underdark. They were imprisoned by illithids, who put Clacker to work as a shepherd for their food supply. However, Clacker's dual mind — that of a pech and a hook horror — allowed him greater resistance to the illithid's mind-numbing powers. He escaped and reunited with his friends. Clacker then had a moment of resurgence, more pech than he had ever been even before his transformation. He raised up a wall of rock to protect Drizzt from Zin-carla of his father, Zaknafein Do'Urden.

Clacker's moment of triumph proved to be a further curse. His hook horror side grew stronger, and he pleaded with his friends to kill him. However, that duty was fulfilled by Zaknafein, who slew Clacker before attacking Drizzt. In death, Clacker reverted to his true form, and his body was committed by his friends to the same pool of acid that Zaknafein, in a resurgence of his free will, jumped into.