If you thought the Moss Mother was the first official boss of Hollow Knight: Silksong, that isn’t the case, as the true one, and one of the most challenging ones for new players, is the Bell Beast. To reach this foe, however, there is one specific skill you need to unlock and some NPCs you might have to meet. But if you manage to beat it, you’ll obtain a function that will help you throughout the whole game.
Bell Beast Boss Guide
Before attempting to fight the Bell Beast in Hollow Knight: Silksong, you need to progress through a specific part of the story where you unlock the Silkspear skill. Without it, you won’t be able to start a fight.
To find the place that unlocks the skill, head to the top part of Mosshome, where you’ll find the bugs that spit acid, and continue moving forward until you reach the shrine-like structure. Interacting with it will unlock the ability.

Besides doing damage, Silkspear will allow you to open certain paths on the map that are covered by a thick silk rope. You need to press R1/RB to use it, and each use will consume silk, so make sure you have some before trying to activate it.
With the skill ready, head east from the shrine until you open a new path and talk with the Moss Druid. Speaking with this NPC isn’t a requirement, but there’s a bench nearby that you can use, and it is also the closest checkpoint to the Bell Beast. Once you activate it, head down until you find the location marked with an arrow pointing to the right. Follow it and use Silkspear to free the Bell Beast and officially start your first boss fight in Hollow Knight: Silksong.

The Bell Beast’s moveset isn’t particularly challenging, but it deals a lot of damage and can kill you with two hits.
Throughout the fight, the Bell Beast will have two main movesโone where it dashes from one extreme to the other at ground level, and you can avoid it by jumping, and if you’re skillful enough, get a hit in by doing Hornet’s plunging attack. You can even chain two hits before the boss goes underground.

The next attack is the one where the Bell Beast will jump from the ground and fly above Hornet. Do not jump. If you do, you’ll get hit and most likely die. Just run to the other end, wait for the Bell Beast to land, and get two hits in before it retreats.

Occasionally, the boss will also emerge from the ground and launch two bells at each extreme of the arena. Move away and then jump to avoid any of the bells.

The second phase will begin once the boss lets out a growl and many bells start falling from the ceiling. The easiest way to avoid them is by going to a corner and staying put. Usually, bells won’t fall on top of Hornet, but if they do, just move in the opposite direction.
After that, repeat the same strategy from above, and be careful with the new bells that will continue falling from the ceiling. Once you defeat the Bell Beast, you’ll get a Silk Heart, a cutscene, and unlock fast travel, which will be pretty useful as you progress through the game.