Go to the pets page and scroll down a little bit. You will see two text boxes with code. Highlight and copy the one which is on the right. It is called the forum code.
Once you have copied all of the code, go to your 'User Control Panel' near the top left of the forum, from here click the 'Profile' tab and select 'Edit Signature' on the left menu. Just right click the text area, and select paste. Voila your pet should appear in your signature after you hit 'Submit'.
Sorry if I've worried anyone. I'm not dead, just too busy to do my usual leisure activities online. Real life always catches up with you lol. If you have any questions please ask another one of our awesome General Helpers<3