Inquisitor's Flail (ISD) from Innistrad, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Rob Alexander
• Card Text:
  If equipped creature would deal combat damage, it deals double that damage instead.
  If another creature would deal combat damage to equipped creature, it deals double that damage to equipped creature instead.
  Equip 2