Appeal to Ridicule

Also called

Appeal To Mockery
The Horse Laugh
Reductio ad ridiculum

A simplistic fallacy in which it is suggested an argument is false by presenting it in a way in which it appears absurd. This often dovetails into Strawman Fallacy or Appeal to Ignorance.

"Queen Alice is using what some may call a cruel and unusual tool to break the resistance of rebel prisoners. I bet many parents would agree! Some are being forced to listen to Barney and Friends sing the "I Love You" song. I think after an hour of that they’ll spill the beans, don’t you?"

If you can mentally picture being locked into a dark room, forced to listen to the "I Love You" song for even an hour (let alone 24/7), it's actually a pretty terrifying prospect. As is such, we can see that stating something in a way that makes it seem nonsensical does not necessarily mean it is nonsensical.

This fallacy differs from reductio ad absurdum, a legitimate debating technique; there, it is demonstrated that an absurd conclusion naturally follows from the underlying logic of an opponent's argument, therefore showing the argument as invalid. Also, just because an argument uses ridicule does not mean it runs afoul of this trope. A person who delivers a withering, logically sound counterattack in a mocking, rude manner is being a jerk. If the argument is still sound, it stands regardless of how insulting the phrasing is.

In terms of tropes, this fallacy often coincides with Too Funny to Be Evil, where an evil character can use this fallacy to get a laugh out of the uneducated masses while dismissing the hero.

Examples of Appeal to Ridicule include:

The most common version is simply repeating your opponent's claim (or part of it) in a silly voice, or, on the internet, repeating it in block capitals with extra leetspeak (teh horrible grammer is optional).
Pejorative nicknames for God or the very concept of a deity such as the Magic Sky Pixie or the Flying Spaghetti Monster. It is designed to disprove God not by presenting evidence, but by rephrasing it in a way that sounds ridiculous.
- While "Magic Sky Pixie" is a common argument from ridicule among atheists, the Flying Spaghetti Monster is actually an example of reductio ad absurdum. The FSM was suggested as a way to demonstrate the absurdity of teaching creationism in schools, by proposing something absolutely ridiculous, but which could be taught in schools under exactly the same logic as those seeking to teach creationism. Of course, most reductio ad absurdum arguments have an element of the appeal to ridicule, as the absurd conclusion is meant to be something that all participants in the discussion would find ridiculous.
Penn & Teller: Bullshit! uses many an Appeal to Ridicule when they believe the argument of their opposition would be obviously wrong to the audience. Since they used the same arrogant, condescending tone when making actual points, it fit in to the show.
Schlock Mercenary got a clear example of this (immediately followed by an example of where it goes once the more civilized discussion is successfully avoided):

Captain Tagon: But the Three-Eff-Cee guy was actually making sense.
Ennesby: That's why the people who disagree choose to mock his message rather than attack it point by point.