Mini-Bosses are typically 16-bit monsters and the consul may chose one in advance in a 16 bit game or two in advance in a super game. The mini boss, once defeated, cannot be re-spawned. In addition the heros draw a single Treasure card when a mini-boss is defeated. The first mini-boss can be summoned once the game reaches 16 bit on the power gauge. The second can be summoned in a super game when the power gauge fills the first time.
Just like Bosses, the boss may remove one status effect every time it rolls a heart and inflicts a wound with an attack.