Hapatra, Vizier of Poisons + Host of the Hereafter

Prerequisites

• You control at least two other creatures with toughness equal to 1.
• You have a way to put a -1/-1 counter on a creature.

Steps

1. 1Put a -1/-1 counter on any creature you control with toughness equal to 1. The creatue dies as a state-based action due to having zero toughness, triggering Hapatra and Host of the Hereafter.
2. 2Resolve the Hapatra trigger, creating a 1/1 Snake creature token.
3. 3Resolve the Host of the Hereafter trigger, putting a -1/-1 counter on any creature you control with toughness equal to 1.
4. 4Repeat from step 2.

Effects

• Infinite death triggers
• Infinite ETB
• Infinite LTB