The Mobile Mastiff is a robotic dog from a Chinese animated show called World Peacekeepers.
The figure is from a line made by M&C Toy Centre that also makes the Army figures called Power Team Elite – World Peacekeepers as well. The two lines are completely separate things though. The animation line is really pretty great for Sci-Fi lovers.
Check the Archive for more figures:
I got mine directly from the manufacturer from their website. They do have a few hoops to jump through but the process is fairly simple still.