Activate Ashnod's Altar by sacrificing another creature that has a +1/+1 counter on it, adding {C}{C}.
When the creature dies, The Ooze triggers, creating a Mutagen token and a creature token due to Stridehangar Automaton.
Activate the Mutagen token by paying {1}, tapping and sacrificing it, putting a +1/+1 counter on the creature token.
Repeat.

Infinite artifact ETB

Infinite artifact LTB

Infinite artifact sacrifice triggers

Infinite creature ETB

Infinite creature LTB

Infinite colorless mana

Infinite death triggers

Infinite creature sacrifice triggers

The Ooze

Ashnod's Altar

Stridehangar Automaton

Cast Basking Broodscale by paying {1}{G}.
When Basking Broodscale enters with a +1/+1 counter on it due to Arwen, it triggers, creating a 0/1 Eldrazi Spawn creature token that'll also enter with a +1/+1 counter on it.
Activate the Eldrazi Spawn by sacrificing it, adding {C}.
When the Eldrazi Spawn dies, The Ooze triggers, creating a Mutagen token.
Activate the Mutagen by paying {1}, tapping and sacrificing it, putting a +1/+1 counter on Basking Broodscale.
Basking Broodscale triggers, creating a 0/1 Eldrazi Spawn creature token that'll enter with a +1/+1 counter on it.
Repeat from step 3.

Infinite +1/+1 counters on a creature

Basking Broodscale

Arwen, Weaver of Hope

Cast Basking Broodscale by paying {1}{G}.
When Basking Broodscale enters, Good-Fortune Unicorn triggers, putting a +1/+1 counter on it.
Basking Broodscale triggers, creating a 0/1 Eldrazi Spawn creature token.
When the Eldrazi Spawn enters, Good-Fortune Unicorn triggers, putting a +1/+1 counter on it.
Activate the Eldrazi Spawn by sacrificing it, adding {C}.
When the Eldrazi Spawn dies, The Ooze triggers, creating a Mutagen token.
Activate the Mutagen by paying {1}, tapping and sacrificing it, putting a +1/+1 counter on Basking Broodscale.
Repeat from step 3.

Good-Fortune Unicorn

Activate Arcbound Ravager by paying {1}{U}, blinking it.
Arcbound Ravager leaves and reenters the battlefield, causing it to enter with +1/+1 counters due to its modular ability, and triggering The Ooze and Deadeye Navigator's soulbond ability.
Resolve Deadeye Navigator's trigger, repairing it and Arcbound Ravager
Resolve The Ooze's trigger, creating a Mutagen token for each +1/+1 counter that was on Arcbound Ravager when it left the battlefield.
Activate Urza's first ability twice by tapping Arcbound Ravager and a Mutagen, adding {U}{U}.
Repeat.

Infinite artifact tokens

Cast all spells in your library

Exile your library

Infinite +1/+1 counters on creatures you control

Infinite Mutagen tokens

Infinite blinking

Infinite blue mana

Infinite creature tokens

Urza, Lord High Artificer

Deadeye Navigator

Arcbound Ravager

Cast Metalwork Colossus by paying {0}, which enters with at least two +1/+1 counters on it due to Bloodspore Thrinax.
When Metalwork Colossus enters, Blasting Station triggers, untapping Blasting Station.
Activate Blasting Station by tapping it and sacrificing Metalwork Colossus.
When Metalwork Colossus dies, The Ooze triggers, creating a Mutagen token for each +1/+1 counter Metalwork Colossus had.
Resolve the Blasting Station ability.
Activate Metalwork Colossus by sacrificing two Mutagens, returning it from your graveyard to your hand.
Repeat.

Combos with "The Ooze"