Once you begin your adventure in Horizon Forbidden West, you’ll be quickly thrown into your first main story mission in which you’ll need to defeat Slitherfang.
It’s a machine reassembling an enormous snake, which has a variety of attacks. Overcoming it isn’t easy.
At the beginning of the fight, your best move will be to aim arrows at Slitherfang’s gears on its neck. It’s one of its weak points, and by damaging it in this area, it will spit out acid.
Luckily, there are various rocks scattered around the fighting area. You should aim to hide behind them when the boss spits out acid and continue your attacks with your bow and arrow when you have the chance. There’s a chance you’ll run out of ammo. If this happens, use one of the rocks as cover and create some more.
At some point in the fight, the machine will fall to the ground. This will be the perfect occasion for you to jump on its head and thrust your spear into it to cause some additional damage. It will also be a great window for you to hit its weak points.
Afterward, a short cutscene will play out, and you will enter the second phase of the fight. Slitherfang will try its best to smash you, so make sure to dodge these attacks. Continue attacking with your bow, and when you see a weapon emitting blue energy on the ground, pick it up and blast Slitherfang with electricity.
It’s important to keep an eye out for the cylinders on its lower chest. When you see them, unload your arrows to significantly weaken Slitherfang.
By the end of the battle, its tail should start to spark, which will imply that it’s about to deal increased damage. At this point, it’s essential that you dodge its attacks and continue to rain down arrows. The boss should die shortly after this phase.