Rats are small mammals of the order Rodentia, distinguishable from mice by their larger size. Rats are typically regarded as vermin or pests, although they can be domesticated and kept as pets, as well as tested in labs. The most common species of pet rat is the Brown/Norway Rat, or Rattus norvegicus.
Body parts from rats, such as the tail and spleen, are used as ingredients in potions, such as the Shrinking Solution. According to Dragon Breeding for Pleasure and Profit, dead rats should be fed to dragons as a reward for good behaviour. Despite this, after just a couple of weeks of growth, Rubeus Hagrid was feeding the young dragon Norberta (known at the time as "Norbert") dead rats by the crate.
A rat is one possible corporeal form of the Patronus Charm. Illyius's Patronus was a rat, which was originally scorned by his villagers for its small size. However, once that Patronus defeated a horde of Dementors sent by Raczidian, the village would forever commemorate any rat-form Patronus is considered to be the most esteemed.The Weasley family kept a pet rat named "Scabbers" for twelve years, owned first by Percy Weasley and later by his younger brother Ron. The fact that Scabbers managed to live for over twelve years greatly surpassed the life expectancy of an average rat, making people think that he was special. However, it was revealed in 1994 that Scabbers was actually an unregistered Animagus named Peter Pettigrew, also known as "Wormtail," who had gone into hiding after Lord Voldemort's disappearance in 1981.
After fleeing Britain following his exposure, Pettigrew made his way to Albania, where he heard from the rats living in the area of Voldemort's presence in the forest.
The Magical Menagerie in Diagon Alley sells sleek black rats that can use their tails as skipping ropes. These may have had a longer lifespan than ordinary rats, as the clerk suggested them to Ron as "something a bit more hard-wearing" than a common garden rat.
While hiding in a cave near Hogsmeade during the 1994–1995 school year, Sirius Black lived off of rats while keeping watch over his godson, Harry Potter, during the events of the Triwizard Tournament.
Sirius regularly fed the hippogriff Buckbeak dead rats while keeping him at Number 12 Grimmauld Place. Whether this or Sirius's own aforementioned diet on rats during the 1994-1995 school year had anything to do with his contempt for Pettigrew, or if it was just out of convenience is unknown.
Known Rat Animagi
- Peter Pettigrew - he learned it along with Sirius Black (dog) and James Potter (stag), in order to companion his friend Remus Lupin, when taking Werewolf form.
- Harry Potter and the Philosopher's Stone (First appearance)
- Harry Potter and the Philosopher's Stone (film)
- Harry Potter and the Philosopher's Stone (video game)
- Harry Potter and the Chamber of Secrets
- Harry Potter and the Chamber of Secrets (film)
- Harry Potter and the Chamber of Secrets (video game)
- Harry Potter and the Prisoner of Azkaban
- Harry Potter and the Prisoner of Azkaban (film)
- Harry Potter and the Prisoner of Azkaban (video game)
- Harry Potter and the Goblet of Fire (Mentioned only)
- Harry Potter and the Order of the Phoenix
- LEGO Harry Potter: Building the Magical World
- LEGO Harry Potter
- LEGO Harry Potter: Years 1-4
- Harry Potter Trading Card Game
- LEGO Harry Potter
- Harry Potter: The Character Vault
- Harry Potter: The Creature Vault