Spyke
Zo0
feddit.de

You can probably do it with Greasemonkey, have you tried that yet?

1

that isn't strictly speaking a gif. imgur (among other image/video/etc hosting) can do a lot of tricks. that ".gifv" at the end of the url makes it present the "gif" as a video (mp4, in this case).

If you change the url to end with just ".gif", then it'll show it as an actual gif

2

You reached the end

How can I scrub GIFs in Firefox / show video playback controls on them? | Spyke