Cygnar Hunter Light Warjack from Privateer Press's "Warmachine' wargame.
According to the game, they are designed to be all terrain warjack killers. The Long Arm Cannon (mounted on the left) fires alchemically hardened penetrator rounds that punch straight through most armor plating. The axe is nothing spectacular, but it allows it to hack its way through dense vegetation.
Made a nice addition to my army this past weekend (even more pleased than before.) Used it as a 'persuader' to keep the warjacks away from my Centurion. Anytime one would try to march across, it got a nice armor-piercing round for its troubles. Didnt get any actual kills, but it did soften up units for the Centurion to tear them apart.

In the book illustration, the Hunter Warjack had a muzzel break on the 'Long Arm Cannon.' Alread happy with the unit, so I wanted to make it look even more interesting. Took my jeweler's drill and drilled out the barrel about 1/8th" the break out with a smaller bit. Took about 20 minutes to pull it off, but got it right the first time.
Also changed a bt of its color scheme, adding a bit more brass. Thinking about adding in kill marks to the barrel or the top of the chassis.