Facehugger

Bestow {3}{b}{b} (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.)
At the beginning of the enchanted creatures
controller's upkeep, that player sacrifices it, then
you may search your library for a Xenomorph
creature and put it into your hand. Sacrifice Facehugger.