He is voiced by Thierry Kazazian in the French Version, and by Lauren Landa in the English version.
He is a small ox-like creature with grayish blue and lighter grayish blue ox horns on his head.
Like all kwamis, Stompp can fly, levitate, phase through solid objects, and carry things that are bigger than him.
Stompp can transform the holder of his Miraculous into a ox-themed superhero by going inside their Miraculous.
As a kwami, Stompp gives the wearer the power of and transforms them into a ox-themed superhero by entering the Ox Miraculous. Although unable to communicate to the wearer while they are transformed, Stompp usually knows what is going on during that time. Whenever the wearer uses Unknown powers, Stompp begins losing power and eventually can't retain the transformation any longer, leaving the nose ring and reverting the wearer back to normal. Stompp is exhausted and out of energy afterwards, so to be able to transform the wearer again, she must refuel by eating food.
Thousands of years prior to the series, Stompp and the other Kwamis traveled the universe, unable to interact with any creatures, particularly humans. This was until a mage forged the Miraculouses, so Stompp and the others could both interact with mankind and grant them the ability to transform into heroes; Stompp and the Ox Miraculous able to give a person the ability to grant other people superpowers.