Shilgengar, Sire of Famine, Trapjaw Kelpie, and Thran Vigil

Prerequisites

• Shilgengar, Sire of Famine on the battlefield
• Trapjaw Kelpie on the battlefield
• Thran Vigil on the battlefield

Steps

1. Activate Shilgengar by sacrificing Trapjaw Kelpie
2. When Trapjaw Kelpie 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 Trapjaw Kelpie
4. Resolve the Shilgengar ability
5. Repeat

Results

• Infinite Blood tokens
• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers