Mephidross Slime is a uncommon Creature — Phyrexian Ooze card from Alchemy: Phyrexia (YONE), collector number 25.
Trample When Mephidross Slime dies, conjure a card named Mephidross Slime into your graveyard. Perpetually double the power and toughness of Mephidross Slime and that card, then shuffle them into their owner's library.