1 - no idea;
2 - could use him for anything you like I reckon. In Warhammer Fantasy Battle, for instance, I think he'd make a nice alternative to a Goblin Fanatic (the ones with the massive ball and chain and the random movement). In this case, his random movenment is justified by the difficulty of controlling the pogo-stick.
He could also be a Standard Bearer. Just because he's half way up the banner pole doesn't make much difference I reckon.
Or maybe he's a Shaman. Maybe he's so high on Fungus Beer he thinks he's riding a Wyvern, or something.
Maybe he's a Squig-Herder. No reason to rely on the official models I reckon.
That's just for Fantasy Battle. Surely, you can do pretty much the same process for almost any fantasy game?
Is the whole team like this? If it is you could invent a new goblin unit for whatever games you do play. Surprising Bouncy Goblin Terrorists. SPRoBOinG-T for short (don't worry, Goblins usally aren't very good at spelling). Rapid random attack goblins that are quite easy to make fall over.
Don't know if any of that helps. Hope so. It's a lovely figure, I'm not really familiar with Blood Bowl, and it's a cool paint job.