Persistent Mosquito

Hatch {1}{b} (Whenever you put this card from your library into the graveyard, you may pay {1}{b}. If you
do, then put this creature from the graveyard onto the battlefield.)
Whenever Persistent Mosquito Enters the Battlefield, it deals 2 damage to each player.
Lifelink, flying
Sacrifice two creatures: Put Persistent Mosquito
from your graveyard into the top of your library.