Snake
From Harry Potter Wiki
A snake (also called a serpent) is a long, thin, legless reptile. The symbol of Slytherin house is the serpent, and the dark wizard Lord Voldemort has a pet snake named Nagini. There are many types of snakes in the magical world, but the biggest and most dangerous of them all is the Basilisk also known as the King of Serpents. The spell Serpensortia creates a snake from the caster’s wand, while the spell Vipera Evanesca gets rid of it. Boomslang skin is an ingredient of Polyjuice Potion. Voldemort's mark, the Dark Mark, is a skull with a snake coming out of its mouth. In 1991 during a trip to a zoo, Harry Potter accidentally set loose a Boa constrictor on his cousin Dudley Dursley. In 1995, Harry Potter witnessed, in dream, the snake Nagini's attack on Arthur Weasley.
[edit] Language
Snakes speak a language called parseltongue. Only a select few wizards can speak this language. They are called Parselmouths. Most Parselmouths were dark wizards. Some known Parselmouths are Lord Voldemort, Salazar Slytherin, Marvolo Gaunt, Morfin Gaunt, Merope Gaunt, and Harry Potter (formerly).
