A snail is a mollusk with a coiled shell. Streelers are a magical variety of snails.
In the 1995–1996 school year, snails were used in Transfiguration class as part of the Vanishing Spell curriculum. As an invertebrate, they presented less of a challenge in vanishing than a vertebrate like a mouse, though it was still considered some of the most challenging magic of its type.
Behind the scenes
- In a certain version of the Philospher's Stone videogame, orange snails appear as enemies to be defeated. Nicholas de Mimsy-Porpington warns Harry that they are very poisonous. They might actually be Streelers.
- Harry Potter and the Chamber of Secrets (video game)
- Harry Potter and the Prisoner of Azkaban (film) (Possible appearance) (indirect as only a shell is seen)
- Harry Potter and the Goblet of Fire 
- Harry Potter and the Order of the Phoenix
- LEGO Harry Potter: Years 1-4