Moss-Pit Skeleton + Chalk Outline + Cloakwood Swarmkeeper + Rook Turret

Moss-Pit Skeleton

Chalk Outline

Cloakwood Swarmkeeper

Rook Turret

How it works

1. Put a +1/+1 counter on a creature you control.
2. Moss-Pit Skeleton triggers, putting it from your graveyard onto the top of your library.
3. Chalk Outline triggers, creating a 2/2 Detective creature token and a Clue token.
4. When the Clue and Detective enter the battlefield, Rook Turret and Cloakwood Swarmkeeper trigger.
5. Resolve the Rook Turret trigger, drawing Moss-Pit Skeleton from your library, and then discarding it.
6. Resolve the Cloakwood Swarmkeeper trigger, putting a +1/+1 counter on it.
7. Repeat from step 2.

This intricate loop centers around Chalk Outline, which acts as the bridge by rewarding you with a Detective and a Clue token whenever Moss-Pit Skeleton leaves your graveyard. That departure is triggered by Moss-Pit Skeleton's own ability, which returns it from the graveyard to the top of your library whenever counters are placed on a creature. Meanwhile, Cloakwood Swarmkeeper grows larger from the resulting token entries, and Rook Turret churns through your deck by letting you draw and discard Moss-Pit Skeleton right back into the graveyard. By seeding the battlefield with these permanent triggers, you turn a single counter placement into an endless cycle of card filtering, token generation, and creature growth.