Mystical Friend

Bestow {g/u} (If you cast this card for its bestow cost,
then it is an Aura spell with enchant creature. It becomes
a creature again if it's not attached to a creature.)
Enchanted creature and Enchantment creature can
act separately as if the enchanted creature wasn't
enchanted and still obtain the enchantment creature's
benefits.
Enchanted Creature can be mutated even if it is a humanoid.