Medusa Worm - SD7-EN014 - Common - 1st Edition from Structure Deck: Invincible Fortress 1st Edition, available at 401 Games Canada.

• Rarity: Common
• Card Text:
  Once per turn, during your Main Phase, you can flip this card into face-down Defense Position. When this card is Flip Summoned, destroy 1 monster on your opponent's side of the field.