Prowling Geistcatcher, Saffi Eriksdotter, and Carrion Feeder

Prerequisites

• Prowling Geistcatcher on the battlefield
• Saffi Eriksdotter on the battlefield
• Carrion Feeder on the battlefield

Steps

1. Activate Saffi by sacrificing it, targeting Prowling Geistcatcher
2. When Saffi dies, Prowling Geistcatcher's first ability triggers, exiling Saffi from your graveyard
3. Resolve the Saffi ability
4. Activate Carrion Feeder by sacrificing Prowling Geistcatcher
5. When Prowling Geistcatcher dies, its second ability and Saffi trigger
6. Resolve the Saffi trigger, returning Prowling Geistcatcher from your graveyard to the battlefield
7. Resolve the Prowling Geistcatcher trigger, returning Saffi from exile to the battlefield
8. Resolve the Carrion Feeder ability, putting a +1/+1 counter on it
9. Repeat

Results

• Infinite +1/+1 counters on Carrion Feeder
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers