Kroax, Vile General

Deathtouch, Double Strike.
Whenever Kroax enters the Battlefield, all
opponents put the top X cards of their library
into the graveyard Where X is the number of
zombies you control.
Whenever Kroax attacks, return target creature
from a graveyard to the battlefield
under your control. Its a Black zombie
in addition to its other types and colors.
{1}{u/b}: Remove Kroax from play, return Kroax
back to the battlefield.