Agent Frank Horrigan + Cryptic Trilobite + Eldrazi Displacer
Agent Frank Horrigan
Cryptic Trilobite
Eldrazi Displacer
Infinite +1/+1 counters on a creatureInfinite blinkingInfinite colorless mana that can only be spent to activate abilitiesInfinite creature ETBInfinite creature LTBInfinite proliferate
How it works
Activate Eldrazi Displacer by paying 2C, blinking Agent Frank Horrigan.
When Agent Frank Horrigan enters the battlefield, it triggers, causing you to put two +1/+1 counters on Cryptic Trilobite.
Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding CCCC that can only be spent to activate abilities.