Jumbo Cactuar, and Bighorner Rancher

Prerequisites

• Jumbo Cactuar on the battlefield
• Bighorner Rancher on the battlefield
• undefined

Steps

1. Declare Jumbo Cactuar as an attacker, triggering its ability, giving it +9999/+0 until end of turn
2. Activate Bighorner Rancher by tapping it, adding 10,000

Results

• Near-infinite green mana