Putrid Goblin + Metallic Mimic + Clickslither

Putrid Goblin

Metallic Mimic

Clickslither

How it works

1. Activate Clickslither by sacrificing Putrid Goblin.
2. When Putrid Goblin dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to Metallic Mimic.
3. Resolve the Clickslither ability.
4. Repeat.

This clever loop turns your battlefield into a self-sustaining engine by playing on the interaction between death and counters. When you sacrifice Putrid Goblin to fuel Clickslither's ability, its persist ability naturally tries to return it with a -1/-1 counter; however, Metallic Mimic enters the picture by setting its chosen type to Goblin, causing the returning creature to enter with a +1/+1 counter instead. Because game rules annihilate opposing +1/+1 and -1/+1 counters through state-based actions, Putrid Goblin's slate is wiped completely clean of counters each time it returns, allowing you to repeat the cycle indefinitely. As this happens, Clickslither grows to an astronomical size, giving you infinite sacrifice and death triggers to win the game on the spot.