Lim-Dûl the Necromancer

Whenever a creature an opponent controls
dies, you may pay {1}{b}. If you do, return that
card to the battlefield under your control.
If it's a creature, it's a Zombie in addition to
its other creature types.

{1}{b}: Regenerate target Zombie.

“They shall kill those whom once they loved.”
— Lim-Dûl the Necromancer