Rat Poisoner

When Rat Poisoner enters the battlefield all opponents with health under 5 loses the game and each player with less then 10 health lose 5 life. When Rat Poisoner enters the battlefield three creatures you control gain "When this creature deals damage to a player, that player loses the game" until end of turn. Creatures you control have Deathtouch. Whenever a rat dies each opponent sacrifices a creature.
{12}{b}{b}{b}{t}: Target player loses the game.