Level: Magma Cone (Autumn Plains)
Climb into the volcano cone at the start of the level to find Hunter in a cave. To get the trophy you need to grab a crystal that Hunter is about to grab.
Follow Hunter and stand over the vents which he waits at, or grab the crystal in mid-air before he snatches it. You'll want to do this on the first part of the challenge, the second would be much harder due to how fast he grabs the crystal.