(Noun) The region of a dog's (or other animal's) anatomy that, when rubbed or scratched, brings great mirth and enjoyment to its recipient. Though its exact location varies between each individual creature, it is almost always located on its underbelly where it is most ticklish. Often identified by the rapid scratching motion of one of its hind legs.
Etymology: The "T" standing for "Tickle", the T-Spot (in name and loose relation) is based off of the "G-Spot" found on Humans, only that the former is completely non-sexual in nature.
"See that? That there's Bandit's T-Spot; a couple inches to the right of his left front leg on his underbelly. See what I mean? I just rub it a couple times and already his hind leg's goin' wild!"