December: 6 -- Rubeus Hagrid* 12 -- Sirius Black 27 -- Nevin Weller 31 -- Tom Riddle/Lord Voldemort*
*We're leaving these dates in, even though we don't have players for these characters yet, because Rowling has told us their birthdays, either in the books or on her website.
By Astrological Sign
Aries: Hannah Abbott, Bellatrix Lestrange, James Potter