What's the problem with GIFs? You're trying to create a violently-shaking GIF for comedic purposes (https://knowyourmeme.com/memes/vibrating-gifs). The GIF editor you're using lets you set a frame duration / delay, so you set it to the lowest possible value for maximum shakage. But when you view the resulting GIF, it's playing much slower than intended, and there are definitely GIFs that play fast