Grimgrin, Corpse-Born, Necrotic Ooze, and Thraben Doomsayer

Prerequisites

• Grimgrin, Corpse-Born in the graveyard
• Necrotic Ooze on the battlefield
• Thraben Doomsayer in the graveyard
• Necrotic Ooze does not have summoning sickness

Steps

1. Activate Necrotic Ooze using Thraben Doomsayer's ability by tapping it, creating a 1/1 Human creature token
2. Activate Necrotic Ooze using Grimgrin's ability by sacrificing the Human, untapping Necrotic Ooze and putting a +1/+1 counter on it
3. Repeat

Results

• Infinite +1/+1 counters on Necrotic Ooze
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers