She is voiced by William Salyers who also voiced Rigby.
Longg is a small dragon-like creature, and she has horns, her eyes are golden.
Like all kwamis, Longg can fly, levitate, phase through solid objects, and carry things that are bigger than her.
Longg can transform the holder of her Miraculous into a dragon-themed superhero by going inside her Miraculous.
As a kwami, Longg gives the wearer the power of weather and transforms them into a dragon-themed superhero by entering the Dragon Miraculous. Although unable to communicate to the wearer while they are transformed, Longg usually knows what is going on during that time. Whenever the wearer uses Weather Dragons, Longg begins losing power and eventually can't retain the transformation any longer, leaving the necklace and reverting the wearer back to normal. Longg 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, Longg and the other Kwamis traveled the universe, unable to interact with any creatures, particularly humans. This was until a mage forged the Miraculouses, so Longg and the others could both interact with mankind and grant them the ability to transform into heroes; Longg and the Dragon Miraculous able to give a person the ability to grant other people superpowers.
- Her name is based on lóng (龙/龍), the Chinese word for "dragon."
- She is the kwami of Perfection.