|Japanese voice actor||Chiwa Saito (small) Takashi Nagasako (big)|
|English voice actor||Mariette Sluyter (small) Jonathan Love (big)|
Tenko is a large tailless yellow fox-like creature with duiker-like horns on his head, ten blue beady eyes (with the main pair three to six times larger than the other pairs), black bat-like wings, brown stripes on his limbs and with no visible ears that helps Ueki awaken his celestial powers.
He can also change his shape to fit onto Ueki's wrist like an arm protector used by goaltenders in ice hockey to give him advice, and seems to be able to communicate with Ueki telepathically. He 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.
Unfortunately, He can only use it to train Heavenly Beings up to 8 levels without dying. This means that he can still use it to another Heavenly Being. When Ueki finds out that Tenko can only train him up to eight levels, Ueki decides to find another way to achieve the final two levels without putting Tenko's life at risk. Has an ability to spit out a large, roundish bunny creature that envelops Ueki and heals him within 12 hours (in the early episodes).
Fairly harsh with Ueki at times, he is nevertheless happy to have found someone who actually needs him. He also is very useful at giving advice in a fight (he is not allowed to fight or he will be sent to Hell); in the jump rope fight he tells Ueki when the rope is coming. Again, he warns Ueki about the Marilyn team's location in the smoke.
After Anon is defeated by Ueki in the final episode, Tenko reappears with other Heavenly Beasts. Tenko is later found not guilty for eating several Heavenly Beings, a crime that never happened in the first place.
Tenko's name probably come from 天子 (てんこ Tenko) mean heaven child.