This is apparently from the last episode. Courage finally realizes how much Eustace calls him "stupid", and how afraid he is. Suddenly, a mysterious teacher comes from out of nowhere, teaching Courage to be perfect. It's all emotional with a good moral, until Courage goes to the bathroom to wash his face. And then... and then... Ever see that creepy Flapjack episode? Yeah, well, this beats that 100x. He starts having conscious nightmares, that make no sense.
Then this guy shows up.
And then, after he's back to normal, a fish comes out of his bathtub for some reason and sets him straight. The teacher explodes into a red mess, and Courage is finally at peace with himself. The Bagg family is never attacked by monsters again, and they live peacefully in the middle of nowhere for the rest of their lives.
D'AWWWWWWWW
Seriously though, I don't remember the whole nightmare part of the episode. I just remember calling BS when a burlap fish came out of the bathtub.
It's a nice ending, and the only episode where Muriel and Eustace aren't in immediate danger, or mistake danger, or any danger.
I'm crying right now for three reasons. One is the ending, the next is the peace, and the third is... im not perfect.