Aliasing animated_gif → animated
Link to alias

Reason:

Because you're supposed to search for animated GIF's with
https://e621.net/post/index/1/type:gif%20animated

The only complaint I would have about this is that searching for gif is buggy, but searching for animated_gif seems to work very consistently. I search for animated_gif more than just gif pretty often just because of that little glitch.