As mentioned in my post Beyond The Powers: The World of Vanaheim, the realm of the Vanir is tribally structured - this has been corroborated by the doxa of multiple individuals from 2007 onward. In no particular order, here is a brief overview of each Vanic tribe and the service they perform:
The Serpent tribe is a small “tribe of introverts” and they live in a series of underground caves in the upper northwestern territory of Vanaheim, in a mixed deciduous and evergreen forest. They specialize in routine “maintenance” energy work as well as catastrophic, catalytic healing. They also serve as catalysts of wyrd, “seething” and creating subtle shifts that “grease the wheels” of change and create “sheddings” that need to happen.