I couldn't think of any hilarious, witty essays that I've written... but I do remember the time where my friends and I made a collage on To Kill A Mockingbird about the supposed Mayella Ewell rape scene (which of course, if you read the book, never actually happened).
What we did was take OJ Simpson, a biking girl, and a happy woman, and conglomerated it into a funny collage.
...To put a long story short, it got rejected by the teacher and the vice principal -- surprisingly, not for the sexual content, but for the fact that the black man, Tom Robinson, was pictured as an evolutionary creature (a decision by my friend purely because it was in the right position, not intended to be hurtful -- srsly), and was deemed racist. We made a new one.
Though we lost the epic creation, I recreated it just now in Photoshop using similar pictures, for your enjoyment: