What's with Orbit's amnesia?

Seriously, what is with his amnesia?
He appeared out of no where, he does not know who he was and he speaks in a foreign language which he later claims its Equestrian.
We see him, at best, as a speaking pony with wings; (should we even call him a pegasus?) Later on, he claims he is a Pennate Pegasus... What the heck is a Pennate Pegasus; (should he even be called a pegasus?)
He fight with skills of our fighter class but uses his mouth to wield his broadsword. This is an impossibility IMO. Don't ask me how he wields a crossbow.... don't go there....
A creature such as this will surely catch the eyes of the enemies. An impossibility that traverse our lands surely will cause the party trouble in the near future...
We, the Despicable will do anything to protect him from harm's way. He is one of us, and we believe he will do the same in his strange foreign way. But it is frustrating that he choose not to seek the Nose Ring as suggested by Agatha! Why court danger when there is a way to avoid it?
So, seriously, what's with his amnesia? Is there something he knows that we don't?

What the Orcs know about Thorrk

After the brutal interrogation of the last surviving orc, the following are what he knows:

1. Bounty on Thorrk is 1000gp
2. Thorrk's father (unknown) is the one that puts up the bounty.
3. Thorrk's father accused Thorrk for killing his wife; Thorrk's mother (also unknown).
4. The bounty notice was put up on all Orc's settlement.
5. Most Orcs heard about this and those relate to them would have heard about it.