Biomancer's Familiar + Crystalline Crawler + Ertha Jo, Frontier Mentor + Kenrith, the Returned King

Mana needed: {G}

WUBRG identity

Commander legal

The 4 combo pieces

• Biomancer's Familiar
• Crystalline Crawler
• Ertha Jo, Frontier Mentor
• Kenrith, the Returned King

How to execute it

1. Activate Kenrith by paying {G}, targeting Crystalline Crawler.
2. Ertha Jo triggers, copying Kenrith's ability, targeting any creature you control.
3. Resolve both Kenrith abilities, putting a +1/+1 counter on Crystalline Crawler and any creature you control.
4. Activate Crystalline Crawler by removing a +1/+1 counter from it, adding {G}.
5. Repeat.

What the combo produces

• Infinite +1/+1 counters on creatures you control
• Infinite card draw for any number of players
• Infinite colored mana
• Infinite draw triggers for any number of opponents
• Infinite lifegain
• Infinite lifegain triggers
• Return all creature cards from all graveyards to the battlefield under your control