Spirit of Nature (Su)
Source: Advanced Class Guide, p. 44
Whenever the shaman is reduced to fewer than 0 hit points, she automatically stabilizes and gains fast healing 1 for 1d4 rounds. At 15th level, this benefit increases to fast healing 3.
True Spirit Ability: A shaman who chooses the nature spirit as her spirit or wandering spirit gains the following ability upon having access to the true version of that spirit.