Putrid Goblin, Thran Vigil, and Phantom Train

Prerequisites

• Putrid Goblin on the battlefield
• Thran Vigil on the battlefield
• Phantom Train on the battlefield

Steps

1. Activate Phantom Train by sacrificing Putrid Goblin
2. When Putrid Goblin dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Thran Vigil triggers, putting a +1/+1 counter on Putrid Goblin
4. Resolve the Phantom Train ability
5. Repeat

Results

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