Wildgrowth Archaic + Crystalline Crawler + Meticulous Excavation

Wildgrowth Archaic

Crystalline Crawler

Meticulous Excavation

How it works

1. Cast Crystalline Crawler by paying 4 in four different colors of mana.
2. Wildgrowth Archaic triggers, causing Crystalline Crawler to enter with four +1/+1 counters on it. It'll enter with a total of eight counters due to its converge ability.
3. Activate Crystalline Crawler eight times by removing eight +1/+1 counters from it, adding 3.
4. Activate Meticulous Excavation by paying 2, returning Crystalline Crawler from the battlefield to your hand.
5. Repeat.