Tenko

Tenko is a Heavenly Beast who is something of a mutation among his kind (he is born as an ancient version of Heavenly Beast, which is a ferocious-looking Godzilla-sized fox-like creature instead of an adorable cat-sized genetically-engineered house pet). He is treated very poorly by Heavenly Beings and Ueki is the first to actually treat him with some kindness and respect. He is able to detect the power level of Heavenly Beings (his eyes lights up and changes colour to red depending on which level the Heavenly Being is on) and because of his mutations has a bigger version of what is called the "awakening organ" that can awaken the hidden powers within Ueki.