Prowling Geistcatcher, Slimefoot and Squee, and Phyrexian Altar

Prerequisites

• Prowling Geistcatcher on the battlefield
• Slimefoot and Squee in hand
• Phyrexian Altar on the battlefield
• available

Steps

1. Activate Phyrexian Altar by sacrificing Slimefoot and Squee, adding
2. When Slimefoot and Squee dies, Prowling Geistcatcher's first ability triggers, exiling Slimefoot and Squee from your graveyard
3. Activate Phyrexian Altar by sacrificing Prowling Geistcatcher, adding
4. When Prowling Geistcatcher dies, its second ability triggers, returning Slimefoot and Squee from exile to the battlefield
5. When Slimefoot and Squee enters the battlefield, it triggers, creating a 1/1 Saproling creature token
6. Activate Phyrexian Altar by sacrificing Slimefoot and Squee, adding
7. Activate Slimefoot and Squee by paying and sacrificing a Saproling, returning Slimefoot and Squee and Prowling Geistcatcher from your graveyard to the battlefield
8. When Slimefoot and Squee enters the battlefield, it triggers, creating a 1/1 Saproling creature token
9. Activate Phyrexian Altar by sacrificing the Saproling, adding
10. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers