Whenever a creature you don't control dies, return it to the battlefield under your control with an additional +1/+1 counter on it at the beginning of the next end step. That creature is a black Zombie in addition to its other colors and types.
The information presented on this site about Magic: The Gathering, both literal and graphical, is copyrighted by Wizards of the Coast.
This website is not produced, endorsed, supported, or affiliated with Wizards of the Coast.