Peter Pettigrew—former Marauder and friend, turned traitorous Death Eater—managed to STAY transfigured for many years without changing back to his human form. But how was he able to do this for as long as he did?

Peter Pettigrew, known by those closest to him as Wormtail, attended Hogwarts School of Witchcraft and Wizardry in the 1970s at the same time as Harry Potter’s father, James.

As both Peter and James were in Gryffindor House together, the pair—alongside Sirius Black and Remus Lupin—became inseparable friends. The four housemates even came up with a name for their little gang: The Marauders.

But after years of friendship, Wormtail betrayed James and his wife Lily, and framed Sirius for his crimes. He then went into hiding as a RAT for the next decade.

How did Wormtail manage this? Keep reading to find out!

The 12-Year Transfiguration of Wormtail: EXPLAINED

How did Peter Pettigrew transfigure himself into a rat?

Peter “Wormtail” Pettigrew didn’t actually TRANSFIGURE himself into a rodent. Instead, he was what the wizarding world calls an Animagus.

You see, in addition to all the mischief the Marauders got up to during their time at Hogwarts, they also worked diligently to support Remus Lupin with his condition as a werewolf. They did this by becoming Animagi, wizards who are able to transition back and forth between their human form and the form of a specific animal.

Aside from Remus, whose monthly transformations into a werewolf were outside of his control, the Marauders gained the ability to transition into the following animals:

• James Potter – A stag the friends called Prongs.
• Sirius Black – A dog the friends called Padfoot.
• Peter Pettigrew – A rat the friends called Wormtail.

Why did Wormtail transform into a rat and disappear?

When Peter betrayed the secret location of the Potter family to Lord Voldemort in 1981, it led to James and Lily’s deaths. A bereaved Sirius then went to confront Wormtail, as Black was the first—and only—person to discover the truth about what Peter had done.

To avoid blame and imprisonment, Wormtail faked his own death and framed Black for his murder. Peter did this by cutting off his thumb, turning into his Animagus form and simply disappearing.

How did Peter Pettigrew get away with murder?

Peter was able to get away with blaming Sirius for his death and other crimes because no one—except the Marauders—knew he could turn into a rat. That and he left his severed thumb at the scene with a devastated and disoriented Sirius.

Since Animagi are legally required to register with the Ministry of Magic, and the Marauders never did, Peter was essentially untraceable. No one knew that Peter could transform into a rat except for James, who died, Sirius, who was charged as a criminal, and Remus, who was still keeping his status as a werewolf quiet.

So, no one thought to look for Peter as a rat. Not to mention that everyone thought he was dead.

How did he stay in his rat form for so many years?

Peter was able to live exclusively as a rat for over a decade because there aren’t any restrictions on how long one can remain in their Animagus form. In fact, even if a witch or wizard decided to live out the rest of their life as their animal self, their life expectancy would still be human.

Basically, it’s not harmful at all for an Animagus to stay in their animal form for as long as they want!

Do you have any thoughts on Wormtail’s decade as a rat? Share them in the comments below!