When Matilda went to the place of Jack's birth, she met his brother and sister, (he had 12 in total) and she was told that he actually ate the runt of the lounge (that's what you call a group of lizards) he ate his little sister!!! That's the reason that we got him, he is the biggest and strongest!

Image from:
https://www.google.com.au/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCKOe6Z6er8gCFWWepgod_AgD8Q&url=http%3A%2F%2Fwww.raisingbeardeddragons.com%2Fbearded-dragon-lighting%2F&psig=AFQjCNHBLNnGxtynyFwQG_87Hc_x10Dktg&ust=1444268676381454