We want revenge!

The Smiling Critters and the Nightmare Critters were enemies. Nightmare Critters always treated Smiling Critters too cruelly. They were too rude, cold and harsh to them, and the Smiling Critters always tolerated it until the day came when the Nightmare Critters realized their guilt and no longer wanted to hurt the Smiling Critters, they began to try to win their friendship, but unfortunately it became too late, as the Smiling Critters began to take revenge. They also became the same as Nightmare Critters, but much worse...