Instructions
Travel to Area 2. The Kelbi live in these woods.
Wander the woods until you spot a Kelbi.
Charge the Kelbi, striking it with quick attacks. If you're fast enough, you'll execute a combo, which temporarily freezes the Kelbi. After enough strikes it will fall to the ground. It is not dead.
Continue hitting the Kelbi while it's on the ground. If you're not fast enough, it will get up and run away. You'll know it's dead when it lets out its death cry.
Carve the Kelbi. You'll get a random trophy, with one in three odds that it is a horn.