This trophy is storyline based and cannot be missed.
Spikey is probably the first tough boss in the game, depending on your level. I'd recommend a minimum of Level 8, preferably Level 9. Spikey will jump up often to ledges on either side of the battleground, where he cannot be hit with melee weapons. Feel free to punish him with the bow when this happens. Otherwise, just charge up your weapon and let loose. Defeating Spikey will yield a Boomerang Orb.