Facehugger

Acid Blood 1, Aggresive Nature
Impregnate (when this creature is blocked by a creature, then attach this card to the blocking creature before damage is dealt)
When this card is attached to a creature, the creature cannot attack, block, or activate abilities
{1}{b} Sacrifice this creature: spawn a black 1/1 chestburster creature token with Offspring and Rapid Growth, then destroy the creature this card was attached to