UPDATE: A VERY custom Triumph Bonneville Scrambler.

And before you as NO, I have no details beyond the photographs. It came from this thread on Adventure Rider.

Info gleaned from the owner in the Adventure Rider thread linked to above:
Ok, a few details, as BT guessed the swingarm and the motor are genuine Triumph, everything else is either custom built or added. The frame is 4139 Cromemoly TIG welded, the forks are KX500, CR500 single rear shock, 2 35mm Mikuni Flat slide pumper carbs, Fuel tank is hand formed aluminum 5+gal,2 sets of wheels, (street/dirt) weight is 382lbs w/o gas. Power is best described as "Beastly"!