Lurking Roper, Elemental Mastery, and Kor Celebrant

Prerequisites

• Lurking Roper on the battlefield
• Elemental Mastery on the battlefield
• Kor Celebrant on the battlefield
• Lurking Roper does not have summoning sickness
• Elemental Mastery attached to Lurking Roper

Steps

1. Activate Lurking Roper by tapping it, creating four 1/1 Elemental creature tokens
2. When the Elementals enter the battlefield, they trigger Kor Celebrant four times
3. Resolve the first Kor Celebrant trigger, causing you to gain one life
4. Lurking Roper triggers, untapping itself
5. Repeat

Results

• Infinite creature tokens with haste
• Infinite ETB
• Infinite lifegain
• Infinite lifegain triggers