Lurking Roper, and Heavy Arbalest

Prerequisites

• Lurking Roper on the battlefield
• Heavy Arbalest on the battlefield
• Heavy Arbalest attached to Lurking Roper
• You have a way to give Lurking Roper lifelink
• Lurking Roper does not have summoning sickness

Steps

1. Give Lurking Roper lifelink, if needed
2. Activate Lurking Roper by tapping it, dealing 2 damage to any target and causing you to gain 2 life
3. Lurking Roper triggers, untapping itself
4. Repeat from step 2

Results

• Infinite damage
• Infinite lifegain
• Infinite lifegain triggers