Before Valve tackles the remaining Team Fortress 2 class updates for the Demoman, Engineer and Soldier, they're going to add a new class. A new page on the Team Fortress 2 Blog introduces gamers to the Guard Dog.

The Guard Dog is your average bloodthirsty hound with a robotic harness. Attached to the harness are two triple-shooting cannons, as well as rockets to give the dog an extra boost of speed. They can also take a more low-tech approach to combat and bite the hell out of the opposing team. When an enemy dies, the Guard Dog can get their scent from the fallen weapon and know their exact location until death or the end of the round.

The new class serves a variety of support functions as well. They can transport medpacks and ammo to teammates on their back or steal them from enemies. On a more disgusting note, the dog is able to refill the sniper's Jarate (i.e. jar of urine) unlockable item.

Valve also provided a list of class-specific Achievements for the dog. It's not clear when this update will go live but usually they don't mention the new Achievements until a patch is about to be released.

Update: It seems this is actually a fan creation. It was re-posted on Team Fortress blog as a sort of "shout out" rather than an admission that it's actually in development. Too bad; it seems like it'd be a fun class to play.