Specimen Collector + Everquill Phoenix + Phyrexian Altar + Ashes of the Fallen

Specimen Collector

Everquill Phoenix

Phyrexian Altar

Ashes of the Fallen

How it works

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