Mabel Pines, Chaotic Twin

When Mabel Pines enters the battlefield, create Waddles, a legendary 2/2 red Pig creature token.
Whenever Mabel Pines or Waddles deals combat damage to a player, look at the top 3 cards of your library, exile one of them until the end of the
turn, and put the rest on the bottom of your
library. Cards exiled this way cost {3} less to cast.