Here is the full list of all 12 Big Fish Legend achievements.
For banishing The Big Rat
For the conquest of the desert
I've learned kangaroo skills of jumps
I'm a real yogi now! I'm not afraid of the quills
Now I can stun my enemies from the distance
For vanquishing the Polar Bear
Seeing underwater, I can swim faster
For vanquish wild birds
For first vanquishing boss
I've become a skilled doghunter. Now I can vanquish any dog with one jump
I've become more attentive and can look down now
For record-height jumps