Graverot Licid

{b}{g}, {t}: Graverot Licid loses this ability and
becomes an Aura enchantment with enchant
creature. Attach it to target creature. You may
pay {b/g} to end this effect.
Enchanted creature gets +1/+1 and "if this
creature would die, return it to the battlefield
under its owner's control, and it's a Zombie in addition to its other types"
Can the Undead be more undead?