Careful Cultivation, Umbral Mantle, and Biomancer's Familiar

Prerequisites

• Careful Cultivation on the battlefield
• Umbral Mantle on the battlefield
• Biomancer's Familiar on the battlefield

Steps

1. Activate the creature with Careful Cultivation and Umbral Mantle attached by tapping it, adding
2. Activate the creature by paying and untapping it, causing it to get +2/+2 until end of turn
3. Repeat

Results

• Infinite green mana
• Infinite power and toughness for a creature until end of turn
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce
• Infinitely large creature until end of turn