Specimen Collector + Everquill Phoenix + Phyrexian Altar + Arcane Adaptation

Specimen Collector

Everquill Phoenix

Phyrexian Altar

Arcane Adaptation

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.