Gaspar, the Malignant Heart

Bestow {1}{g}{g} (If you cast this card for its bestow
cost, it's an Aura spell with enchant creature. It
becomes a creature again if it’s not attached to a
creature.)
Enchanted creature has Transfigure {1}{b}{b}
({1}{b}{b}, Sacrifice that creature: Search your library
for a creature card with the same mana value as the sacrificed creature, put that card onto the battlefield,
then shuffle. Transfigure only as a sorcery.)