Lanayru (Spirit)
Lanayru is one of the four Light Spirits in Twilight Princess. The name "Lanayru" is most likely a reference to the goddess Nayru. It protects the Lanayru Province and appears in the form of a serpent. In the game the Lanayru spirit is the only one that has an intricate shrine built in its likeness around its spring, and it is also mentioned that local Hylians make regular visits to pay respect to the spirit.
When Link succeeds in removing the Twilight from the Lanaryu Province, Lanayru explains how the Fused Shadows, which Link is searching for, were formed by the power of a race of dark magic wielders. But the Gods summoned the three light spirits to intervene. The light spirits sealed away their magic into the fused shadows and the interlopers were chased across Hyrule into the Gerudo desert where they were then banished to the Twilight Realm by the Gods.
When Zant attacks Midna and Link at Lanayru's spring after they find the last Fused Shadow, the Lanayru spirit appears and attempts to attack Zant, but is pushed back. This is the only time one of the spirits is seen to attack an enemy directly.