Malcolm, Keen-Eyed Navigator + Magmaw + Amoeboid Changeling + Xorn

Malcolm, Keen-Eyed Navigator

Magmaw

Amoeboid Changeling

Xorn

How it works

1. Activate Amoeboid Changeling by tapping it, causing Magmaw to gain all creature types until end of turn.
2. Activate Magmaw by paying 1 and sacrificing another nonland permanent, dealing 1 damage to an opponent.
3. Malcolm triggers, creating two Treasure tokens.
4. Activate a Treasure by tapping and sacrificing it, adding 1.
5. Repeat from step 2.

This clever loop transforms our fiery elemental into an honorary buccaneer, thanks to Amoeboid Changeling's ability to grant every creature type to Magmaw. Once Magmaw is officially a Pirate, its own sacrifice-and-damage ability conveniently triggers Malcolm, Keen-Eyed Navigator to generate loot whenever it deals damage to our opponents. To ensure the fire keeps burning, Xorn steps in to amplify our gains by churning out an extra Treasure token every single time Malcolm triggers, giving us more than enough fuel to pay Magmaw's activation cost indefinitely and incinerate the table.