A blocking Obstagoon is a nigh-irrestible force, capable of halting the movement (given a particular composition, at least) of whole armies. One Obstagoon became renowned as a fearsome bandit lord long held out against Zacian, Zamazenta, and their trainers – individuals known better to history as Galar's kings.
The rationale for its resistance changed over the years, from protecting the free peasantry to restoring a deposed ex-king, but its blocking position on the important trade route of Wyndon Road, on the site of the modern route 10, offered decades of frustration to the Galarian state. This Obstagoon often allowed solo travelers to cross, which gave rise to legends about its noble spirit and meant it was not quite as total a barrier as the Snorlax who often impede traffic in Kanto by falling asleep on its roads; messengers traveled past with ease, even crossing on foot when the customary flying-types shied away from the hail. But despite the Crown's best efforts, it obstructed the movement of officials and could not be dislodged from its mountain pass home, until the day when, depending on which version you believe, the Obstagoon either accepted the war was lost and accepted free passage to the Wild Area or died of old age.
The use of the letter 'x' to represent the negative, so common in contemporary video games (and even, in some countries, a common offline gesture) originates with Obstagoon's habit of crossing their arms when blocking their opponents. It was most famously used in a loosely historical game which transplanted the legend of the Wyndon Road Obstagoon to the mountains of Hoenn, in order to fit it into the world of Sengoku-era Ransei.