People who've watched the movies: There are three undocumented animagi... James Potter, Sirius Black, and Peter Pettigrew.
People who've read the books: There are FOUR... James Potter, Sirius Black, Peter Pettigrew, and Rita Skeeter.
Me: Well...
Actually, there were FIVE undocumented animagi... You all probably think I'm crazy, but there were five... James Potter, Sirius Black, Peter Pettigrew, Rita Skeeter... and Dolores Umbridge.
Just think about it, the mauraders all had nicknames they used when they were in their animagus forms. (As you probably know...)
James= Prongs
Sirius= Padfoot
Peter= Wormtail
It turns out that Umbridge had a nickname too... They called her Nagini.
P.S. Neville Longbottom is now my favorite character soully because he killed Umbridge. I'm sorry Dolores, but I must not tell lies!
