Gray Slaad
{2}{B}Creature — Frog Horror
As long as there are four or more creature cards in your graveyard, this creature has menace and deathtouch.
Gray Slaad // Entropic Decay
{2}{B} // {1}{B}
Creature — Frog Horror // Sorcery — Adventure
Oracle Text
Entropic Decay
{1}{B}Sorcery — Adventure
Mill four cards. (Then exile this card. You may cast the creature later from exile.)