Varagle, Rat Emperor

Other rats you control have +2/+2, Hexproof, Indestructible, and Doublestrike.
Rat spells you cast cost {0} mana.
{b}{b}{b}{b}: Search your library for a rat and put it
on the battlefield.
{x}, {t}: Create X 1/1 rats with deathtouch. Repeat
this an amount of times equal to the number of
rats you control.
Whenever this creature takes damage you may sacrifice that many rats instead.