Cercerus is its own thing and is unrelated to the Pokemon Houndoom (:
It is a creature found in the Roobix Region in my project titled Fabled Friends. In this world, the creatures (or mons/fakemon) are known as Friends!
It possesses the power of flame and darkness, and each of its three heads has a different personality! It is also capable of undergoing a transformation with the power of the Galaxia phenomenon, a type of magical power that arises from the power of the galaxies that allows a Friend to transform! Cercerus is the main companion of the most notorious villain in Roobix, a woman named Diedre who owns a multimillion dollar company named Venatici Incorporated that specializes in the creation of robotics. Notably, in my piece titled "Escape the Sector", it is the only creature there that embodies flames, whereas every other Friend there is an insect type of being.
That is because the insect type of Friend is the most common type of creature is the most popular to use in Venatici Incorporated, and Diedre's Friend is capable of besting all of them because it has the superior typing that is powerful against them. (Not to mention its incredibly high level thanks to the efforts of Diedre's coaching.)
Cercerus was created for Diedre in particular because the constellation of Canes Venatici is supposed to resemble two dogs running! It was also inspired of Greek Mythology as well, with Cerberus, or the three headed dog that guards the gates to the underworld. I'd say that Cercerus is a fitting companion to the woman who raises hell!
