为 鸭嘴熊 寻找最佳的标准套牌，包括其胜率、热度，以及该牌在万智牌：竞技场中的合法赛制！
Defender
When this creature enters, mill two cards. (Put the top two cards of your library into your graveyard.)
As long as there is a Lesson card in your graveyard, this creature can attack as though it didn't have defender.
