Island spirits texture?

I am browsing the databuild packages of the Sulani expansion but I cannot seem to find the base texture for the island spirits. I am not 100% sure they do have a texture (maybe just a 2D billboard?" but I think there should be something somewhere that defines their "shape" as I would love to make a texture replacement for them, alter their colours etc.
Does anyone have any tips where I could find this texture to edit?