I spent several days on my entry, trying to get it just right. XD In the end, I settled on this. Also, I must say that everyone elses are excellent. :) I hope more people enter though. :D
Anyway, here's my entry~
Ghost: Well, it's a ghost. That would be it's type and it's loosely based on the generic, white ghost.
Christmas: Ahem, it has a Fluttershy, I mean, Christmas tree on it's head as a sort of headgear. XD Not to mention there are festive themes throughout, such as the stars for eyes and the vivid colours used, similar to the colours on Christmas trees.
Past: Probably the hardest one to implement. I kinda interpreted this as time, hence the time symbol on its 'stomach' and the clock on the top.
Anyway, I'd just like to point out some other things. I tried to portray greed (Scrooge is seen as this) in the sprite by giving it mutilple arms, and no, it's not coincidental. I genuinely tried to portray greed, ansd the original (before I updated it) only had two arms. So yeah, I basically tried to interpret the novel. XD
Anyway, i guess I've babbled on for too long, so yeah. I'll stop now. I am quite proud of the finished product though, and I wish everyone else the best of luck, and merry Christmas, and for those who don't celebrate it, happy holidays! :D