Plaguemaw Beast, Intruder Alarm, and Herd Baloth

Prerequisites

• Plaguemaw Beast on the battlefield
• Intruder Alarm on the battlefield
• Herd Baloth on the battlefield
• Plaguemaw Beast does not have summoning sickness
• Herd Baloth has at least one +1/+1 counter on it
• You control at least one additional creature

Steps

1. Activate Plaguemaw Beast by tapping it and sacrificing another creature, putting a +1/+1 counter on Herd Baloth
2. Herd Baloth triggers, creating a 4/4 Beast creature token
3. When the Beast enters the battlefield, Intruder Alarm triggers, untapping all creatures
4. Repeat

Results

• Infinite +1/+1 counters on Herd Baloth
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite proliferate
• Infinite sacrifice triggers