Malcolm, Keen-Eyed Navigator, Havoc Jester, and Amoeboid Changeling

Prerequisites

• Malcolm, Keen-Eyed Navigator on the battlefield
• Havoc Jester on the battlefield
• Amoeboid Changeling on the battlefield
• You control at least one Treasure token
• Amoeboid Changeling does not have summoning sickness

Steps

1. Activate Amoeboid Changeling's first ability by tapping it, causing Havoc Jester to gain all creature types until end of turn
2. Activate a Treasure token by tapping and sacrificing it, adding one mana of any color
3. Havoc Jester triggers, dealing 1 damage to any opponent
4. Malcolm triggers, creating a Treasure token
5. Repeat from step 2

Results

• Infinite colored mana
• Infinite damage