The Evil Within

Story related, and cannot be missed.
During Chapter 12: The Ride you will encounter a mutated spider boss while you're riding on the bus. There are two encounters with this boss and a small segment where you must fight off a few waves of enemies. This boss's attacks are easily avoided and you'll want to save your more powerful ammo types if you can. Hit the boss with a few explosive bolts. Avoid his leg by moving forward or backward on the bus aisle, or occasionally ducking into stealth crouch if his leg sets up for a sweep attack. Switch to your handgun or your shotgun to deal with the three worms he spawns from his sacks and then go back to damaging the boss. The worm enemies do drop ammo, so handgun is my first weapon choice on these little guys.

When the boss backs off, you can save your ammo. He wont catch up to the bus again until after you fight the next set of enemy waves. The bus will come to a full stop and a series of zombies will attack you from above. It is important to conserve ammo here because very few enemies will actually make it on the bus to drop ammo for you. Focus on taking on the snipers, dynamite/molotov throwers. The more molotovs you let by, the less room you'll have to move around and avoid damage. Let Joseph worry about the other enemies unless they get on the bus.

Once the waves are done, you'll be on the move again. Deal with the boss the same way you did before. This trophy will unlock when the boss is dead.