Horobi, Death's Wail, Shadow Alley Denizen, and Ogre Slumlord

Prerequisites

• Horobi, Death's Wail on the battlefield
• Shadow Alley Denizen on the battlefield
• Ogre Slumlord on the battlefield
• You have a way to put a black creature onto the battlefield under your control

Steps

1. Put a black creature onto the battlefield under your control
2. Shadow Alley Denizen triggers, targeting any nontoken creature an opponent controls
3. Horobi triggers, destroying the targeted creature
4. When the creature dies, Ogre Slumlord triggers, creating a 1/1 Rat creature token
5. Repeat from step 2

Results

• Destroy any number of nontoken creatures whenever a black creature enters the battlefield under your control
• Destroy any number of nontoken creatures whenever a creature dies