With Community Day only a few days away, Niantic have dropped the exclusive move for Mamoswine. Despite it being an Ice/Ground type, Mamoswine will get the exclusive move of Ancient Power, a move it could learn in the core games and it was needed to evolve Piloswine into Mamoswine. You needed to get Piloswine to learn the move, then level it up once to trigger its evolution.
I had hoped it would have been something that benefitted from STAB but we’ll see how it performs. Its not going to be a top tier Rock attacker but it might serve as a decent gym defender to surprise Fire attackers like Moltres who aren’t expecting a Rock move.
In addition to that, trainers can receive up to 5 Sinnoh Stones per day, from trainer battles during the Community Day weekend. On the actual Community Day, you can get up to 10 Sinnoh Stones, an additional 5 from practice battles with Team Leaders on top of the 5 already stated.
Also don’t forget to use your Star Pieces if you have any, its triple stardust from catches. For more information on Community Day, you can refer to this post .