Board Thread:Plants vs. Zombies: Garden Warfare/@comment-25411806-20140822082011/@comment-24275721-20140822135722

The Zombie O.O wrote:

Yeah, i got 1 Laser Bean card, and 1 Melon-pult. Mainly from the Yetis xD The Yetis drop only COSTUME cards, not UPGRADE cards.

You need to play the Gargantuar or Zomboss Challenges to get Upgrade puzzle pieces.