Exchange of Words + Devoted Druid + Lair of the Hydra

Prerequisites

• Lair of the Hydra does not have summoning sickness.

Steps

1. 1Activate Lair of the Hydra's last ability by paying , making it a 1/1 land creature until end of turn.
2. 2Cast Exchange of Words by paying .
3. 3Exchange of Words enters the battlefield, exchanging the text boxes of Devoted Druid and Lair of the Hydra.
4. 4As the turn ends, Lair of the Hydra stops being a creature.
5. 5On your opponent's upkeep, activate Lair of the Hydra using Devoted Druid's first ability by tapping it, adding .
6. 6Activate Lair of the Hydra using Devoted Druid's last ability, putting a -1/-1 counter on it and untapping it.
7. 7Repeat from step 5.

Effects

• Infinite green mana
• Infinitely large creature