#1 King Dice:
King Dice is a very difficult boss to defeat because in order to beat him, you have to beat a lot of other mini bosses, and thats just to be able to damage him.
#2 Grim Matchstick:
His last phase is very had to stay alive because he gets 3 heads and starts shooting fire balls at you. and one of the heads will periodically turn into a flamethrower
#3 Rumor Honeybottoms:
Her attacks are difficult to evade because she gets really close to you and starts spewing honey that slows you down.