Eko

Ecko(pronounced Eko) was once one of the three sons of Leinad until he became the embodiment of the dark ooze.

Ecko's name is from the word eco from Jak and Daxter but Ecko also shares his name(by pronunciation)with the antagonist of Karas, Eko Hoshunin.

story
Ecko was the youngest of the three and the most ignored. He like Syrus was jealus of how strong Haul was. His jealousy led to him being compelled to kill Syrus and Haul. Failed at killing Syrus, Ecko had fallen into a vat of black toxic fluid known as the black ooze. It changed him into the most horrifying creature ever known by many.