Give Bellowing Aegisaur indestructible by any method.
Activate Walking Ballisata by removing a +1/+1 counter from it, dealing 1 damage to Bellowing Aegisaur.
Bellowing Aegisaur triggers, putting a +1/+1 counter on each other creature you control.
Repeat from step 2.

Infinite +1/+1 counters on most creatures you control

Bellowing Aegisaur

Walking Ballista

Give Bellowing Aegisaur indestructible by any method.
Activate Triskelion by removing a +1/+1 counter from it, dealing 1 damage to Bellowing Aegisaur.
Bellowing Aegisaur triggers, putting a +1/+1 counter on each other creature you control.
Repeat from step 2.

Triskelion

Give Bellowing Aegisaur indestructible by any method.
Deal damage to Bellowing Aegisaur.
Bellowing Aegisaur triggers, putting a +1/+1 counter on each other creature you control.
Scurry Oak triggers, creating a 1/1 Squirrel creature token.
The Squirrel enters the battlefield, triggering Warstorm Surge, dealing 1 damage to Bellowing Aegisaur.
Repeat from step 3.

Infinite creature tokens

Infinite creature ETB

Scurry Oak

Warstorm Surge

Cast Electroduplicate by paying its mana cost, creating a token copy of Bellowing Aegisaur.
Activate a mana-producing permanent you control by tapping it, adding at least {G}.
Activate Wayta by paying {G} and tapping it, causing Cacophodon and the nontoken Bellowing Aegisaur to fight each other, with each only taking 1 damage due to Temple Altisaur.
Cacophodon and Bellowing Aegisaur each trigger twice.
Resolve all Bellowing Aegisaur triggers, putting two +1/+1 counters on each other creature you control.
Resolve both Cacophodon triggers, untapping the mana-producing permanent and Wayta.
Repeat from step 2, alternating between having the token and nontoken Bellowing Aegisaur fight Cacophodon.

Infinite +1/+1 counters on creatures you control

Wayta, Trainer Prodigy

Cacophodon

Temple Altisaur

Electroduplicate

Give Bellowing Aegisaur indestructible by any method.
Deal damage to Bellowing Aegisaur.
Bellowing Aegisaur triggers, putting a +1/+1 counter on each other creature you control.
Scurry Oak triggers, creating a 1/1 Squirrel creature token.
The Squirrel enters the battlefield, triggering Terror of the Peaks, dealing 1 damage to Bellowing Aegisaur.
Repeat from step 3.

Terror of the Peaks

Give Bellowing Aegisaur indestructible by any method.
Deal damage to Bellowing Aegisaur.
Bellowing Aegisaur triggers, putting a +1/+1 counter on each other creature you control.
Scurry Oak triggers, creating a 1/1 Squirrel creature token.
The Squirrel enters the battlefield, triggering Pandemonium, dealing 1 damage to Bellowing Aegisaur.
Repeat from step 3.

Pandemonium

Give Bellowing Aegisaur indestructible by any method.
Deal damage to Bellowing Aegisaur, with all but 1 of that damage being prevented by Temple Altisaur.
Bellowing Aegisaur, Ghyrson Starn, and Spark Double trigger.
Resolve the Spark Double trigger, dealing 2 damage to any target.
Resolve the Ghyrson Starn trigger, dealing 2 damage to Bellowing Aegisaur, with all but 1 of that damage being prevented by Temple Altisaur.
Spark Double and Bellowing Aegisaur trigger.
Resolve the Bellowing Aegisaur trigger, putting a +1/+1 counter on each other creature you control.
Resolve the Spark Double trigger, dealing 2 damage to Bellowing Aegisaur, with all but 1 of that damage being prevented by Temple Altisaur.
Ghyrson Starn and Bellowing Aegisaur trigger.
Repeat from step 5.

Ghyrson Starn, Kelermorph

Spark Double

Activate a mana-producing permanent you control by tapping it, adding at least {G}.
Activate Wayta by paying {G} and tapping it, causing Cacophodon and Bellowing Aegisaur to fight each other, with each only taking 1 damage due to Temple Altisaur.
Cacophodon and Bellowing Aegisaur trigger twice.
Resolve both Bellowing Aegisaur triggers, putting two +1/+1 counters on each creature you control.
Resolve both Cacophodon triggers, untapping the mana-producing permanent and Wayta.
Repeat from step 2, alternating between having Cacophodon fight Bellowing Aegisaur and Dominion Saboteur to ensure neither dies due to lethal damage.

Combos with "Bellowing Aegisaur"