Satoru Umezawa, Peregrine Drake, and Great Whale

Prerequisites

• Satoru Umezawa on the battlefield
• Peregrine Drake in hand
• Great Whale on the battlefield
• Great Whale does not have summoning sickness and cannot be blocked and killed by an opponent
• You control up to five lands that can tap to produce at least

Steps

1. Declare Great Whale as an attacker
2. When Great Whale is unblocked, activate up to five lands you control by tapping them, adding at least
3. Activate Peregrine Drake's ninjitsu ability by paying and returning Great Whale from the battlefield to your hand, putting Peregrine Drake from your hand onto the battlefield tapped and attacking
4. Peregrine Drake enters the battlefield, untapping up to five lands
5. Activate up to five lands you control by tapping them, adding at least
6. Activate Great Whale's ninjitsu ability by paying and returning Peregrine Drake from the battlefield to your hand, putting Great Whale from your hand onto the battlefield tapped and attacking
7. Great Whale enters the battlefield, untapping up to seven lands
8. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB
• Infinite mana lands you control can produce
• Infinite untap of lands you control