Appa, Steadfast Guardian, Ashnod's Altar, and Animate Dead

Prerequisites

• Appa, Steadfast Guardian in the graveyard
• Ashnod's Altar on the battlefield
• Animate Dead in hand
• available

Steps

1. Cast Animate Dead by paying its mana cost, returning Appa from your graveyard to the battlefield with Animate Dead attached to it
2. When Appa enters, it triggers, airbending Animate Dead
3. Animate Dead triggers
4. Holding priority, activate Ashnod's Altar by sacrificing Appa, adding
5. Resolve the Animate Dead ability, doing nothing
6. Cast Animate Dead from exile by paying , returning Appa from your graveyard to the battlefield with Animate Dead attached to it
7. Repeat from step 2

Results

• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinite storm count