I'm familiar with Santa Claus's mythology.

But I have to be honest and say I don't feel he's an appropriate character for a crossover RP. Maybe if it was specifically based off of mythology or something(which would probably be a pretty good RP), but not for this.

Honestly I'd feel the same way about anyone using any real-world mythological figure, unless they were being used as a character from a canon setting or from an OC setting that was not set up just to be straight out of mythology(for example, if you used, say, characters from Percy Jackson that would be fine, but not if you just used Zeus right out of Greek Mythology).

I'm sorry, but this is my final word on the matter.