Christel, Beak and Antler

{t} Tap: Add X mana of any one color, where X is the number of creature cards in an opponent's graveyard.

{1}{w}Create a 1/1 white Flamingo creature token for each Elf you control.
{2}{g}Create a 3/3 green Elk creature token for each Elf you control.
{2}{u/b}Each opponent mills two cards.