Ulamog's Dreadsire + Thornbite Staff + Carrion Feeder

Ulamog's Dreadsire

Thornbite Staff

Carrion Feeder

How it works

1. Activate Ulamog's Dreadsire by tapping it, creating a 10/10 Eldrazi creature tokens.
2. Activate Carrion Feeder by sacrificing the Eldrazi token.
3. When the Eldrazi token dies, Ulamog's Dreadsire triggers, untapping Ulamog's Dreadsire.
4. Resolve the Carrion Feeder ability, putting a +1/+1 counter on it.
5. Repeat.

By equipping Thornbite Staff to Ulamog's Dreadsire, we unlock a terrifying feedback loop where the Eldrazi's tap ability does double duty: tapping to create a 10/10 token also grants the creature a built-in untap trigger whenever anything dies. Carrion Feeder acts as the crucial sacrifice outlet, instantly devouring the newly created token to feed itself a +1/+1 counter. That death immediately satisfies Thornbite Staff's untap condition, allowing Ulamog's Dreadsire to tap again for another colossal token and letting you repeat the cycle indefinitely.