"Nagini is a gigantic snake, at least twelve feet long, who belongs to Voldemort."
From the Story
Discovered in Book 4, Chapter 1, The Riddle House
"Nagini is in the Riddle House with Voldemort and Wormtail. Voldemort is being sustained by milk produced by Nagini. Nagini passes Frank Bryce in the corridor of the Riddle House. She enters the room in which Voldemort and Wormtail are speaking, seemingly ignoring the Muggle. Nagini is able to communicate with Voldemort, as he is a Parseltongue, and can therefore talk snake language; she informs him that Frank is standing outside the door. Nagini lies on the hearth-rug as Voldemort talks to the old man. She lifts her head, hissing slightly, when Wormtail starts to move Voldemort's chair to face Frank."