Requires

Squirrel Wrangler must be on the battlefield. Phyrexian Altar must be on the battlefield. Mana Echoes must be on the battlefield. Drownyard Temple must be on the battlefield. Mana needed:

Steps

1. Activate Squirrel Wrangler by paying and sacrificing Drownyard Temple, creating two 1/1 Squirrel creature tokens.
2. Both Squirrel tokens enter the battlefield, triggering Mana Echoes twice.
3. Resolve both Mana Echoes triggers, adding for each Squirrel on the battlefield.
4. Activate Drownyard Temple by paying , returning it from your graveyard to the battlefield tapped.
5. Activate Phyrexian Altar by sacrificing a Squirrel token, adding .
6. Repeat.

Results