I agree, dont ruin christmas for him as a child!!! I know santa isnt real now obviously, but my mom still likes to tell me he isLOL ... It just ruins all the fun of christmas!!!
Sex, drugs, etc.. is a whole other topic and that will come up in a few years, and its best to let your child know they can talk to you about that stuff, but those thing have nothing to do with Santa... LMFAO!!
And as for the snake stockings, i think it would be best to get a large stocking and call it the "Snake Room Stocking", and fill it with some supplies you already need for the snake room (Spray bottles, tongs, temp gun, hides, etc)...
Good Luck
~Brandon