The Great Goblin, Xenograft, and War Elemental

Prerequisites

• The Great Goblin on the battlefield
• Xenograft on the battlefield
• War Elemental on the battlefield

Steps

1. Put a counter on War Elemental
2. The Great Goblin's first ability triggers, as War Elemental is a Goblin, Orc or Army due to Xenograft, dealing 2 damage to an opponent
3. War Elemental triggers, putting a +1/+1 counter on it
4. Repeat from step 2

Results

• Infinite +1/+1 counters on a creature
• Infinite damage