of course santa is real, he is just dead and has a wildly exaggerated legendary status. Saint Nicolas of Turkey was known for giving gifts to all the god-fearing children in the area. all that other junk (reindeers, elves, etc) was attached to him from various pagan traditions, as christians just invented christmas to try and compete with pagan holidays around the same time of year, adopting many of their traditions to try and get some converts. interestingly enough, a great deal of world cultures, often without any knowledge of the traditions of others, have some kind of winter festival, and strangely consistently some form of bearded father christmas figure, whether it be a god attached to it or created solely for that holiday.
so in short, in all likelyhood santa was a godlike alien being who spread tidings and good cheer to human societies in their infancy, then left. over time, we intergrated that magical fatman into our religions and cultures, and eventually arrived at a conglomerate of all our experiences (and coca cola ad campaigns) to get the heavily skewed vision of santa we have today.