The p'hiili were a species of aquatic beings that originated from the planet of Yuuzhan'tar. These creatures' genetic information was taken by the Yuuzhan Vong, also native to Yuuzhan'tar, when they launched their invasion of another galaxy. Following the capture of Coruscant in 27 ABY, the sentient Yuuzhan Vong recreated the p'hiili and introduced them to the terraformed planet.
These creatures produced a distinctive burring sound. They were commonly placed in ponds or other bodies of water near Yuuzhan Vong dwellings, functioning as a natural warning system. Their tendency to consume anything within their reach, classifying them as omnivores, further enhanced their utility as guardians.
Prior to the Yuuzhan Vong War that began in 25 ABY, these aquatic organisms were originally from the planet of Yuuzhan'tar. The Yuuzhan Vong initiated this war to invade the galaxy of the New Republic in search of a new home after the destruction of Yuuzhan'tar. The genes of the p'hiili were taken by the Yuuzhan Vong with the intention of later recreating them. Following the conquest of Coruscant, the capital of the New Republic, in 27 ABY, the p'hiili were recreated and introduced to the newly terraformed world. This world had been renamed Yuuzhan'tar in remembrance of the Yuuzhan Vong's original homeworld. In 28 ABY, on the new Yuuzhan'tar, p'hiili were observed in a pool of water near a shrine dedicated to the Yuuzhan Vong god Yun-Harla, their calls mingling with those of the ngom.
The p'hiili made their debut appearance in Greg Keyes' 2003 novel, The New Jedi Order: The Final Prophecy, which was the second-to-last book in The New Jedi Order series.