为 无畏巨河马 寻找最佳的史迹套牌，包括其胜率、热度，以及该牌在万智牌：竞技场中的合法赛制！
When this creature enters, put two −1/-1 counters on target creature you control.
Whenever you put one or more −1/-1 counters on this creature, remove a -1/-1 counter from another target creature you control.
