ok let me explain this
For an Animated .gif file as your Sigmature
Put it on a website if you havent already(so it has a url)
do [img]http://www.1upclan.info/images/tesla_avatar.gif[/img](replace it with your URL)
This will come out with this:
For an Animated Profile Pic:
For it to be Animated you can no directly upload it to 1up
Upload it to some Image hosting site
then link it using the image tags [img] and [/img]