a happy trail that has been cut, shaved, styled, clipped, or dyed to be the single gaudiest, ugliest, corniest, tackiest, most pretentious or most interesting thing about the hippy, hipster, deviant, or weirdo wearing it (there's no proof yet that any woman has ever done this anywhere). Usually something lame and supposedly counterculture like a tree, offensive logo, optical illusion, or, at its worst, an actual picture of a person or scene. Or, of course, Che Guevara.
When done right, it's usually a video game logo or something random or horrifying enough it actually seems appropriate to put on the happy trail.
"What the--that guy had that picture of Obama shaved into his hippy trail! Dude, wear a shirt, for America's sake!"
"Ugh, that's just foul."
"Woah, what the hell is that on his hippy trail?"
"Who, that guy? I dunno. Why are you looking?"
"That's the triforce!"
"Holy crap! Hey, half-naked dude! You win!"