The following article can contain spoilers! Enter at your own risk!
Phone Guy was the former manager of The Krusty Krab, appointed by Mr. Krabs himself. He helps the player by giving them information about the restaurant and the animatronics, as well as current events. Phone Guy is one of the only protagonists in Five Nights at the Krusty Krab.
It's also speculated that it's the Phone Guy in the good ending, where he's reaching out to Squidward Tentacles in the white void.
In Five Nights at the Krusty Krab, Phone Guy will contact the player every night. He tells the player of important news, and tips that will help the player survive the night.
- It is believed that the figure at the good ending for Five Nights at the Chum Bucket is Phone Guy, and that Phone Guy is an animatronic himself.