Dirty Wererat (ODY) from Odyssey, available at 401 Games Canada.

• Rarity: Common
• Finish: Normal
• Artist: Daren Bader
• Card Text:
  B, Discard a card from your hand: Regenerate Dirty Wererat.
  Threshold — Dirty Wererat gets +2/+2 and can't block. (You have threshold as long as seven or more cards are in your graveyard.)