Warhounds are one of the many types of large war robots known as Titans from games workshop's warhammer 40k universe. They are part of the 6mm scale epic wargame. They have dog-like heads, and their feet resemble paws. They are bipedal, looking a little like the AT-ST from Star Wars, but their legs are more reminiscent of the hind legs of a dog than a chicken. The overall effect, though bizarre at first, is unique and interesting, especially when you add in the gothic church-like aspects of much of its armour. They are one of the smallest Titans, and look almost cute beside their larger cousins such as the Warlord and Reaver Titans.
Warhounds are scout Titans, and are primarily used for armed reconnaissance by the Titan legions of the human Imperium. They are around 50 feet tall, which is small for a Titan, but seems excessive for a scout unit until you consider the threats that are likely to be present in a theatre of war where a Titan legion, a group of up to a hundred 100 foot tall humanoid war robots, has been deployed. Warhounds operate in pairs, and are attached to larger units such as a Titan Battle group - a group of 3 of the heavier battle titans - when fighting in a major engagement. In battle, they are normally used to harass the enemy's flanks, assault lightly defended positions or support larger Titans or formations of armour or infantry. If they are left exposed in the open they will almost certainly be destroyed quickly, as they have only two void shields and relatively thin armour to protect them. Because of their large size and high visibility relative to tanks, for example, they will attract a large amount of enemy fire if they do not make full use of their impressive manoeuvrability.
Warhounds can carry two main weapons, but because of their small size and the low power output of their plasma reactor - relative to those of other Titans - they are limited in their choice of weapon. Because of their impressive speed, many commanders favour equipping them with close-ranged weapons, such as the giant flame-thrower known as the inferno cannon which is devastatingly effective against infantry, or the plasma blastgun, a powerful but short-ranged weapon that will easily destroy most tanks and can even be effective against unshielded Titans. One of the classic weapon combinations for a warhound detachment is to equip one with two turbo laser destructors, a powerful laser weapon (with a cool name), and the other with a plasma blastgun and a vulcan mega-bolter, a huge rapid-fire version of the bolt gun (also with a cool - if somewhat silly - name). This combination makes the detachment highly effective at taking out unsupported enemy Titans. The mega-bolter and turbo lasers are effective at knocking down shields at short ranges, while the speed of the Warhounds allows them to bring the lasers and plasma gun to bear on the weaker rear armour of the enemy. In this way, the weaker Titans can easily take on a much larger opponent through effective teamwork.
I have a Warhound miniature on my desk, but he is sadly nameless at present. Feel free to /msg any suggestions. Free cookies to the person who sends the best suggestion. (You have to come to Edinburgh to collect, though.)