Slow - Passive: When you spotlight the Zombie and they don't have a token on their stat block, they can't act yet. Place a token on their stat block and describe what they're preparing to do. When you spotlight the Zombie and they have a token on their stat block, clear the token and they can act.
Rend Asunder - Action: Make a standard attack with advantage against a target the Zombie has Restrained. On a success, the attack deals direct damage.
Rip and Tear - Reaction: When the Zombies makes a successful standard attack, you can mark a Stress to temporarily Restrain the target and force them to mark 2 Stress.