The Strawman Fallacy

The Strawman Fallacy is a fallacy that occurs when an argument is made by setting up an opponent as a caricature, often in a way that is easy to knock down. This is often done by misrepresenting the opposing view in an extreme or absurd manner, making it easy to argue against the strawman, while actually addressing a weaker version of the opposing viewpoint that was never really presented.

Example:

Person A says "The Earth is round."
Person B says "Oh no, it's actually a giant pineapple with a face and a hat!"
This is a Strawman Fallacy because Person B is misrepresenting Person A's view as a ridiculous and easy-to-defeat version, rather than actually addressing the real issue of the Earth's shape.