Kenrith, the Returned King, Earthcraft, Agatha of the Vile Cauldron, and Myr Scrapling

Prerequisites

• Kenrith, the Returned King on the battlefield
• Earthcraft on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• Myr Scrapling in the graveyard

Steps

1. Activate a basic Swamp by tapping it, adding
2. Activate Kenrith's fifth ability by paying due to Agatha, returning Myr Scrapling from your graveyard to the battlefield
3. Activate Earthcraft by tapping Myr Scrapling, untapping the basic Swamp
4. Activate Myr Scrapling by sacrificing it
5. Repeat

Results

• Infinite +1/+1 counters on creatures you control
• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers