Cayth, Famed Mechanist, Mana Echoes, and Pestermite

Prerequisites

• Cayth, Famed Mechanist on the battlefield
• Mana Echoes on the battlefield
• Pestermite on the battlefield
• available

Steps

1. Activate Cayth by paying and tapping it, creating a copy of the Pestermite token
2. When the Pestermite token enters the battlefield, it and Mana Echoes trigger
3. Resolve the Pestermite trigger, untapping Cayth Resolve the Mana Echoes trigger, adding for each creature you control that shares a type with the Pestermite token
4. Repeat

Results

• Infinite ETB
• Infinite colorless mana
• Infinite creature tokens