Phone Guy is a character from Fnaf, he first appeared in Retarded64: Freddy's Spaghetteria he tells Mario some advice about the Animatronics and that he’s “Fucked”.
He again appears in Retarded64: Return to Freddy's Spaghetteria to tell Welcome Mario to his new job.
He made a cameo in Retarded64: Revenge of Freddy's Spaghetteria where he freaks out Luigi.
During SMG4: Freddy's Ultimate Custom Spaghetteria. Mario shoots His phone in anger, though it is soon found out that it is immortal in some way.