Cosmoem

Cosmoem is a 111/111 with Taunt that has the ability to kill an ally Pokemon, then deal 85 damage to the enemy player. If you buff its ATK or HP with Nihilego or Floette, there is an easter egg where Cosmoem's ability becomes "At the end of your turn, kill all enemy Pokemon", but keeps the Taunt. This is helpful for protecting Cosmoem.