Sech'kellyn were homunculi crafted by the Jaghut and modeled on the Forkrul Assail. They were "white as bone" with "too many, knees, ankles, elbows" and were able to procreate. Their usual activity was to kill anything in sight, but it was possible to bind them to one's will with a sorcerous collar and give them commands.
The mage, Mizzankar Druble, possessed six Sech'kellyn but grew weary of the mental control needed to tame their spirits. He summoned a demon to take over the effort, but mistakenly called upon a god-thing far more powerful than he expected. The demon took possession of the statues and left Mizzankar's tower.
Some time later, the six Sech'kellyn were buried under what became Avoidance Alley in the Toll's City. They were discovered and brought to the city's court mage who soon went mad and drowned himself in a bowl of water. A soldier who touched the statues and did not ritually purify himself afterwards died in a freakish accident.
When the city's ruling Chanters tried to hire the Crimson Guard they included the six statues with their proposed payment. Toll's City palace guard, Sater, saw an opportunity to make herself wealthy and she stole the gold and silver bars meant for the Guard along with the Sech'kellyn. Perhaps under the statues' influence, she could not bring herself to throw them overboard in her escape on the Suncurl.
When the Suncurl reached Laughter's End the statues were finally able to send a call to their old master. They nearly beat necromancer, Korbal Broach, to a pulp when he went to the ship's strong room to study them. Bauchelain killed one with his sword before the enormous god-thing burst from the sea, broke into the ship's strong room, seized the remaining statues, and departed for the deep.