I'm Confused what the Difference is between this and It Was His Sled.

This troper understands this trope, and once saw it inverted to amazing effect. Since I don't know how to use spoiler tags, I'll jut say that I knew a character in The Sixth Sense was supposed to end up having been dead all along... but didn't recognize the character when they came on screen. It was like Tomatoin the Mirror two times over.

Which is a penis and at this point a shaggy dog, which means nothing to see here, move along.