Specimen Collector, Everquill Phoenix, Ashnod's Altar, and Maskwood Nexus

Prerequisites

• Specimen Collector on the battlefield
• Everquill Phoenix in hand
• Ashnod's Altar on the battlefield
• Maskwood Nexus in hand
• available

Steps

1. Cast Everquill Phoenix for its mutate cost by paying , putting it under or over a non-Human creature you control
2. Everquill Phoenix triggers, creating a Feather artifact token
3. Cast Maskwood Nexus by paying
4. Activate Ashnod's Altar by sacrificing Specimen Collector, adding
5. When Specimen Collector dies, its second ability triggers, creating a copy of the Feather token
6. Activate a Feather by paying and sacrificing it, returning Specimen Collector from your graveyard to the battlefield
7. When Specimen Collector enters the battlefield, its first ability triggers, creating a 1/1 Squirrel and a 0/3 Crab creature token
8. Repeat from step 4

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite colorless mana
• Infinite creature tokens