You mean a gif?
You just post it like any other img
{Square bracket} img=YOUR LINK HERE and then close it with another square bracket}

But I just tried your image and I think its the site.
[img=http://i.imgur.com/rhmVhEw.gif]

DONT CRY TOM D:

Here use this one
http://i.imgur.com/rhmVhEw.gif
[url=http://i.imgur.com/rhmVhEw.gif]