An hour or so ago, I hit level 75 with my Hunter... it was an anticlimactic sort of level up as I picked it up from killing a lower-leveled mob while looking for Rhino meat for one of the cooking dailies. Still, that brings me one level closer to joining my guild in the endgame, which is always good to know.
As for the accidental achievement noted above, I picked one up called Northern Exposure. I got it in the middle of performing the Kalu'ak daily quest in Kamagua, wherein I had to get two sea bulls to fall in love and, presumably, mate.
The thing that unlocked it... Attacking a larger than average penguin for no apparent reason, only to realize it was a rare enemy. Below, you'll see screenies of King Ping and the subsequent acquisition of this little achievement.
And the Achievement:
1 hour ago