Lord Skitter, Sewer King + Void Attendant + Earthcraft + Xenograft

Lord Skitter, Sewer King

Void Attendant

Earthcraft

Xenograft

How it works

1. Activate a basic Forest by tapping it, adding .
2. Activate Void Attendant by paying 1 and putting a card an opponent owns from exile into their graveyard, creating a 1/1 Eldrazi Scion creature token.
3. When the Eldrazi Scion enters the battlefield as a Rat due to Xenograft, Lord Skitter's first ability triggers, exiling a card from an opponent's graveyard.
4. Activate Earthcraft by tapping the Eldrazi Scion, untapping a basic Forest you control.
5. Activate the Eldrazi Scion by sacrificing it, adding C.
6. Repeat.

This clever engine transforms the battlefield into a recursive loop by utilizing Xenograft to redefine every creature you control as a Rat, perfectly setting the stage for Lord Skitter, Sewer King to constantly trigger whenever new rodents appear. By activating Void Attendant, you spend the mana generated from a basic Forest (untapped via Earthcraft) to pull an exiled card back into an opponent's graveyard and birth an Eldrazi Scion token. That very Scion enters as a Rat, fueling Lord Skitter, Sewer King to exile another card, while Earthcraft lets you tap the token to untap your land and Void Attendant provides the crucial Eldrazi Scion fodder to repeat the cycle indefinitely.