Bulb

From Celestial Compass Roleplaying Wiki

Due to their capacity for ambulation, bulbs have long been believed to be the unmatured forms of treants. This hypothesis, however, has been recently disproved by a team of dedicated naturalists who, after capturing several of the seedkin and observing them for two score years in a controlled environment, documented no further growth from their original state. The bulb's ability to walk appears simply to be a trait developed to allow the seedkin access to richer soils.