Peter (Wormtail) Pettigrew (Scabbers) 
Birth Notes
Sirius and Remus Lupin reveal that Pettigrew is an Animagus who takes the form of a small rat. Called "Wormtail," he had become the secret-keeper for James Potter and his wife Lily Evans when Harry was a baby, in hopes that Lord Voldemort would pursue Black instead. However, he betrayed the Potters to Voldemort in order to gain the Dark Lord's favour. During the confrontation with Sirius on that fateful night, it was actually Pettigrew who blasted the muggles and then transformed himself to escape with the other rats down into the sewers. He left behind a finger, successfully faking his own death and framing Black for his and the Potters' deaths.
Here is a link to the TNG Page
General Notes
Pettigrew had masqueraded as Scabbers, the pet rat owned at first by Percy Weasley, then by his brother Ron. It has not been revealed how Peter, as Scabbers, managed to get into the Weasley family. However, Pettigrew used his time with them to his advantage: he remained alert for any news about Voldemort or Black. None of the Weasleys took particular note that "Scabbers" outlived a common garden rat and had a missing toe.
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Connections & Relationships
Wormtail has an unspecified social relationship with Percival (Percy) Ignatius Weasley.He/she has an unspecified social relationship with Ronald (Ron) Bilius Weasley.