Crystalline Nautilus

Crystalline Nautilus

Enchantment Creature - Nautilus | Power/Toughness: 4 / 4 (CMC 3)
Bestow (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.)
When Crystalline Nautilus becomes the target of a spell or ability, sacrifice it.
Enchanted creature gets +4/+4 and has "When this creature becomes the target of a spell or ability, sacrifice it."