The Jolly Balloon Man, Mana Echoes, and Umbral Mantle

Prerequisites

• The Jolly Balloon Man on the battlefield
• Mana Echoes on the battlefield
• Umbral Mantle on the battlefield
• You control at least one additional nonlegendary creature
• available

Steps

1. Activate The Jolly Balloon Man by paying and tapping it, creating a token copy of a nonlegendary creature you control that is a 1/1 Balloon with flying and haste
2. When the creature token enters the battlefield, Mana Echoes triggers, adding for creature you control that shares a creature type with the creature token
3. Activate The Jolly Balloon Man by paying and untapping it, giving it +2/+2 until end of turn
4. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite colorless mana
• Infinite creature tokens with haste
• Infinite token copies of each other creature you control with haste
• Infinitely large The Jolly Balloon Man until end of turn