A person who has recieved a video game for Christmas, despite the fact that thousands of others already had the game. When they play they get their ass shat on. One can always tell a Christmas noob because 2 - 5 days after christmas, they're level of skill/rank is much lower than others'.
Wow, that kid just got raped, he must be a christmas noob.
How is that kid only a level 17?!?! Oh, wait...christmas noob.