This is a significant part of his character, as it:
* Mirrors his Patronus: The stag is also his Patronus, highlighting his bravery, loyalty, and selflessness.
* Connects him to his son: Harry Potter's Patronus is also a stag, indicating a powerful connection between father and son.
* Represents his transformation: The stag symbolizes James's growth and development from a reckless prankster into a courageous and responsible man.
It's important to note that James's Animagus form was never explicitly stated in the books, but rather deduced through the following clues:
* Harry's Patronus: As mentioned, Harry's Patronus is a stag, strongly suggesting that James's Animagus form was the same.
* James's connection to the stag: In *Prisoner of Azkaban*, James is shown to be particularly fond of stags and even keeps a stag's head mounted in his home.
* The Marauder's Map: The map specifically mentions a stag, which is often understood to be James's Animagus form.
While J.K. Rowling hasn't directly confirmed it, the clues strongly suggest that James Potter's Animagus form was indeed a stag.