Here's a breakdown of who he is:
* A former friend of James Potter, Sirius Black, and Remus Lupin: He was part of the Marauder group at Hogwarts, but was generally considered the least brave and most cowardly of the four.
* Betrayed James and Lily Potter: He informed Voldemort about their whereabouts, leading to their tragic deaths. This act made him a traitor and a murderer in the eyes of the wizarding world.
* Fled to Voldemort's service: He became Voldemort's most devoted servant, acting as a spy and performing tasks like stealing the Philosopher's Stone.
* Survived the Killing Curse: Contrary to what many believed, he did not die with Voldemort. He was only gravely injured, surviving by taking on the form of a rat.
* Reunited with Voldemort: He served Voldemort for years, helping him regain power and ultimately leading to the return of the Dark Lord.
* A coward at heart: His actions throughout the series demonstrate his cowardice and lack of moral compass. He is willing to betray anyone to save his own skin, even if it means harming others.
Wormtail's character arc is one of the most complex in the series. He starts as a seemingly harmless friend who turns into a traitor and Voldemort's loyal follower. This transformation, driven by fear and self-preservation, makes him a tragic and unsettling character.