Dominion Saboteur, and Hammerhead, Maggia Boss

Prerequisites

• Dominion Saboteur on the battlefield
• Hammerhead, Maggia Boss on the battlefield

Steps

1. Activate Hammerhead by sacrificing Dominion Saboteur
2. When Dominion Saboteur dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Choose to have it enter as a copy of the creature with persist with a +1/+1 counter on it
4. Remove a +1/+1 counter and a -1/-1 counter from Dominion Saboteur as a state-based action
5. Resolve the Hammerhead ability
6. Repeat

Results

• Infinite +1/+1 counters on a creature
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers