Surly Badgersaur, Library of Leng, and Rook Turret

Prerequisites

• Surly Badgersaur on the battlefield
• Library of Leng in hand
• Rook Turret on the battlefield
• available

Steps

1. Cast Library of Leng by paying
2. When Library of Leng enters, Rook Turret triggers, causing you to draw a card and then discard a land card
3. The discarded card is put on top of your library instead of into your graveyard due to Library of Leng
4. Surly Badgersaur triggers, creating a tapped Treasure token
5. When the Treasure enters the battlefield, Rook Turret triggers, causing you to draw a card and then discard a land card
6. Repeat from step 3

Results

• Infinite draw triggers
• Infinite self-discard triggers
• Infinite tapped Treasure tokens