'Goats on Fire!' is the cry of the deranged soul, the vapours of the opium s/he's smoking. In the world of the deluded, there is an entertainingly wide spectrum of crazy. 'Goats on Fire!' used as an adjective ('S/he is utterly Goats on Fire!') identifies those in the manic street preacher/may benefit from medication category of the insane. In Poeish usage, in a parody word salad context, 'Goats on Fire!' is employed to identify deliberately that the parody of fervour at hand has been written by a believer of said quality.
'Goats on fire!' first appears, to this author's knowledge, in the comments threadspam of an infamous troll residing, also to our latest knowledge, in Montreal, Canada. See also this article.
The phrase may have been coined by Brad Neely.