Putrid Goblin + Goblin Trashmaster + Thunderous Velocipede

Putrid Goblin

Goblin Trashmaster

Thunderous Velocipede

How it works

1. Activate Goblin Trashmaster 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 Thunderous Velocipede.
3. Resolve the Goblin Trashmaster ability.
4. Repeat.

This clever little loop turns Putrid Goblin into an endless sacrifice engine right under the nose of Goblin Trashmaster, letting you crack artifacts infinitely. The secret sauce that breaks the persist mechanic wide open is Thunderous Velocipede, whose replacement effect drops a +1/+1 counter onto the Goblin just as it enters. Since a persist creature returning with a counter is supposed to stay dead next time, that incoming counter instantly nullifies the -1/-1 counter Putrid Goblin would normally carry, resetting its ability so it can die again and again.