I really don't know with this one...I definitely say it's part Psychic though. The antlers could be like branches which could make it part Grass type, but then again... Psychic/Normal Psychic/Grass Normal?
I put by bets on at least secondary Grass...if not main.
As for Psy...could be. I do think they will do something akin to Lugia and Ho-oh, where one is elemental (Fire) but the other something else instead of what youd expect (Psy instead of Water) So Grass and Dark mascots sounds about right.