James's Animagus form was that of a stag, which earned him his nickname,
Lily was an animagus too, when Voldemort attacked, she transformed in front of him so that she could attempt to escape. Voldemort hit her with a spell which locked her in her form as a twisted way of leaving her alive for Snape. Harry never noticed but there was always an animal watching him as he grew up.
There's no evidence for or against her knowing.
“A creature I wouldn't want to kiss . . . a spider!” Harry figures out the riddle, and realizes that a spider is about to attack. But what he doesn't realize is what I now believe: that the spider in the maze is Professor Snape, in his Animagus form. It is Spider/Snape who bears down on Cedric and Harry.
They are James Potter, Sirius, Wormtail, Skeeter, McGonagall, Talbott Winger, and an unnamed witch who can turn into a cat. The fact that there are so few Animagi just causes us fans to want to know more about them. After all, they are some of the most unique characters in all of Harry Potter.
“Technically, it's a ferret.” Barty Crouch Jr. may have been completely wrong to transfigure Draco as a punishment, but he was within the same family of what I believe Draco's Animagus form would take, which is the stoat, or ermine.
For example: if Viktor Krum can transfigure his head into a shark's, like he does in Goblet of Fire, that doesn't mean he is an Animagus. Transfiguration is a form of spell-casting, whereas becoming an Animagus is forever. And yes, he could turn into a falcon.
Peter Pettigrew's Animagus form was a rat. Colloquially, a "rat" is a snitch or informant. Webster's also lists the following possible definition: "a contemptible person: such as... one who betrays or deserts friends or associates."
In Harry Potter and the Prisoner of Azkaban, Remus Lupin shared that it took his fellow Marauders – James, Sirius and Peter – until their fifth year at Hogwarts to finally become Animagi and keep him company in his werewolf form.
Strikingly, Harry's Patronus was a stag and his mother Lily's was a doe, a female deer, showing that the family's characters were in harmony and formed part of the same animal group.
Snape definitely knew that Sirius was an animagus after PoA since he was in the room while Lupin was telling the story about him becoming a werewolf and how his friends became Animagus. Snape also has the added incentive that he hates Sirius' guts.
Her conscious refusal and readiness to die seals the charm and, thus, Harry's fate as the Boy Who Lived. Although James has the same intention of saving his family while knowing that he is likely to be killed, he is not granted an alternative for his sacrifice to put Lily and Harry under magical protection.
Harry discovers this in Prisoner of Azkaban, when his Patronus turned out to be a stag, his father's Animagus form.
Following both ordeals, Ginny grew into a confident young woman. Her and her friends followed in the footsteps of a previous generation, completely unbeknownst to them, and became Animagi at the age of fourteen, to support their best friend, Maisie Cattermole. Ginny took the form of a grey mare.
Also one's Patronus and Animagus forms can be the same. So by that logic it is fairly plausible that Dumbledore's Animagus form could have been a Phoenix.
Because there was no need for him to become one. Besides he had lot of other important stuff going on in school unlike his father and his friends who were determined to help Lupin.
When James learned what Sirius did, he stopped Snape before he reached the Shrieking Shack, saving his life. Snape, however, had seen Lupin in werewolf form and was sworn to secrecy by Dumbledore.
It turns out (naturally) that Sirius was framed, and even after their twelve-year separation he and Lupin remain fiercely devoted to each other. By book 5, the two of them are living together in secret.
Sirius's early life proved unhappy; he had come to hate most of his relatives, in particular his mother. He rejected his family's pure-blood elitism and reverence for the Dark Arts. At Hogwarts, rather than be sorted into Slytherin like the rest of his family, Sirius was placed in Gryffindor.
His animagus form is a black cat with a white mark across its chest - a likeness to the small scar Regulus bears after a particularly bad fight he had with Sirius as a child.
Known Animagi
Falco Aesalon — Falcon; the first recorded Animagus; the registration system was not in existence in his time.
Was Voldemort an Animagus? No, Voldemort was not an Animagus. He didn't see any reason to become an Animagus despite being a gifted wizard and knowing a lot of magic. This may simply be because his sole purpose was to obtain immortality and become the strongest wizard who could control the world around him.
Godric Gryffindor never died. He is an animagus that took the form of a phoenix and can no longer transform back to his human form due to it being so old.
An Animagus is still a witch or wizard, and Aurors can fight werewolves like Fenrir Greyback, so it's very unlikely Grindelwald is either of those.
The third Harry Potter movie - The Prisoner of Azkaban introduces the Hogwarts alum, and Werewolf, Remus Lupin.