Remus Lupin was also known as “Moony” to his friends because he transformed into a werewolf during the full moon. harrypotter.wikia.com
Remus Lupin as a werewolf. harrypotter.wikia.com
J.K. Rowling uses lots of charactonyms throughout the Harry Potter series. Merriam Webster defines charactonym as “a name for a fictional character that suggests a distinctive trait of the character.” In Harry Potter and the Prisoner of Azkaban, a new Defense Against the Dark Arts teacher is hired and his name is Remus Lupin. Lupin is very similar to the word lupine, an adjective which means of or relating to a wolf. Lupine comes from the Latin word lupus meaning wolf. Lupin’s name betrays what he actually is, a werewolf! I like trying to decipher the charactonyms that J.K. Rowling uses in her books, because it makes the books more interesting and exciting.
the word explorer 
That is sooooo AWESOME!
– Lexie
http://www.whatlexieloves.blogspot.com
I would also like to add that the name “Remus” is taken from one of the founders of Rome. Relevant here is that Remus, along with his brother Romulus, were rescued and nursed by a
wolf! http://en.wikipedia.org/wiki/Romulus_and_Remus
As a Harry Potter nerd, I’ve got to say that charactonyms are the greatest. Did Rowling use one to create Voldemort’s name, or just come up with the name “Tom Marvelo Riddle” and scramble it?