Ivy Lane Denizen, Devoted Druid, and Flourishing Defenses

Prerequisites

• Ivy Lane Denizen on the battlefield
• Devoted Druid on the battlefield
• Flourishing Defenses on the battlefield
• Devoted Druid does not have summoning sickness

Steps

1. Activate Devoted Druid's first ability by tapping it, adding
2. Activate Devoted Druid's second ability by putting a -1/-1 counter on it
3. Flourishing Defenses triggers, creating a 1/1 Elf Warrior creature token
4. The Elf Warrior enters the battlefield, triggering Ivy Lane Denizen, putting a +1/+1 counter on Devoted Druid
5. Resolve the Devoted Druid ability from step 2, untapping it
6. Repeat

Results

• Infinite creature tokens
• Infinite ETB
• Infinite green mana