Gaako's form is that of a short pudgy green dragon with purple eyes. She has three horns on the top of her head with one horn being located on her forehead and the other two on the back of her head. On the sides of her face, she has three spikes. On her back, she has two small light green wings. She has sharp fangs that are seen when she opens her mouth. She has six blue spikes with two located on the back of her head and four on her tail. She is seen wearing the school female uniform.
Gaako is shown to be calm.
Eiko Oni - She is Gaako's best friend.
- Gaako appears more prominently in the anime series, and not as much in the manga series. However she does appear briefly in chapters 30 and 152.