Symbol of Forest Aura and also used to represent aura cost on cards.
As one of the many aura types in MetaZoo Forest Aura is characterized by the green border and it's massive amount of beasties and cards with this typing. Stated as the second largest aura typing behind Dark Aura typing, Forest is focused on growth and meant to be played in/around nature. It also has a tendency to be a great typing for generating aura. Playing a Forest Aura means you have a weakness to Fire Aura and strengths against Water Aura.