ok, you have to upload your gif animation onto a web space .. if you dont have webspace, let me know, i can put it on mine for you no trouble

you go to your user cp , then edit profile, then you will see a section called Signature. Copy the location of where your animated gif is located into there, using the image tags, see the code i have put below, thats what i used. I didn't close off the image tags as you can see because if i did the code wouldn't show here .. don't forget to close off the brackets in your cp! ...

img]http://www.nebulaart.com/misc/toby2.gif[/img

let me know if you need help!