Mini Thor

Source
Mini Thor is a vanity pet which you get from buying the Collector's Edition of . The pet binds to the Battle.net account on which StarCraft is activated, and is given by mail to each and every character you create on that account.

Pet Journal
''Powerful artillery of the terran army. The Thor is always the first one in and the last one out!''

Description
Players are mailed this pet by The WoW Dev Team:

Trivia
Mini Thor, the Wings of Liberty Collector's Edition reward, is based off the Terran unit.