The Great Goblin + Imagecrafter + War Elemental

The Great Goblin

Imagecrafter

War Elemental

How it works

1. Activate Imagecrafter by tapping it, causing War Elemental to become a Goblin until end of turn.
2. Put a counter on War Elemental.
3. The Great Goblin's first ability triggers, as War Elemental is a Goblin due to Imagecrafter, dealing 2 damage to an opponent.
4. War Elemental triggers, putting a +1/+1 counter on it.
5. Repeat from step 2.