Hounds are the small dogs that attack you at various points throughout the game. To kick a hound, simply approach it and press "circle" to grab it, and Kratos will drop kick it across the room, or even into other enemies. You can usually kick hounds two or three times each. If the hound is low on health, Kratos will grab it and rip its jaws instead of kicking it.
There are numerous encounters with hounds throughout the game, so this trophy is pretty easy to get as long as you start your kicking right away and work on it consistently.