Spike Feeder, and Heroic Feast

Prerequisites

• Spike Feeder on the battlefield
• Heroic Feast on the battlefield

Steps

1. Activate Spike Feeder's second ability, removing a +1/+1 counter from Spike Feeder and gaining at least 2 life
2. Heroic Feast triggers, putting a +1/+1 counter on Spike Feeder
3. Repeat

Results

• Infinite lifegain
• Infinite lifegain triggers