Kenrith, the Returned King, Earthcraft, Agatha of the Vile Cauldron, and Extruder

Prerequisites

• Kenrith, the Returned King on the battlefield
• Earthcraft on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• Extruder 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 Extruder from your graveyard to the battlefield
3. Activate Earthcraft by tapping Extruder, untapping the basic Swamp
4. Activate Extruder by sacrificing it
5. Repeat

Results

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