The Watcher in the Water, and Dire Undercurrents

Prerequisites

• The Watcher in the Water on the battlefield
• Dire Undercurrents on the battlefield
• You have a way to draw a card during an opponent's turn

Steps

1. Draw a card during an opponent's turn
2. The Watcher triggers, creating a 1/1 Tentacle creature token
3. When the Tentacle enters the battlefield, Dire Undercurrents' first ability triggers, causing you to draw a card
4. Repeat from step 2

Results

• Infinite card draw
• Infinite draw triggers
• Near-infinite creature tokens
• Near-infinite ETB