Hollow Knight Silksong has more than 40 bosses spread across Pharloom, but only a fraction appear in strict order. Some are mandatory roadblocks tied to the main story, while others are hidden or tied to quests. This guide lists every confirmed boss in the game so far, showing both the main path encounters and the optional challenges you can tackle for rewards or completion.

All Mandatory Bosses in Order

Moss Mother

Location: Moss Grotto
The first boss of the game, found above the Bench in the Ruined Chapel. She swoops low with stinger dives, slams the ceiling to drop rocks, and summons Moss Grubs. Attack after her swoops or when clearing her summons.

Bell Beast

Location: The Marrow
Freed from silk with the Silkspear, Bell Beast charges and leaps around the arena. Later, bells rain from above. Defeat her to unlock Pharloom’s fast-travel system.

Lace (First Encounter)

Location: Deep Docks
Lace fights with dashes, dives, and flurries that test precision. She teleports to marked circles before unleashing combo slashes. Dodge early and punish during recovery.

Fourth Chorus

Location: Far Fields
A massive mechanical foe on crumbling platforms. Its limb swings smash the ground and collapse parts of the arena. Use the Drifter’s Cloak to float over attacks and drop stalactites to deal big damage.

Sister Splinter

Location: Shellwood
She fights with claw swipes and vine summons, crowding the arena with minions. Focus on upward strikes to hit her head and clear adds quickly to avoid getting overwhelmed.

Widow

Location: Shellwood, above Bellhart
Widow uses silk bells that bounce and strike diagonally, plus charges and dives that erupt spikes from the ground. After her first phase she revives, adding heavier bell barrages. Plasmium Phial is highly recommended for phase two.

Cogwork Dancers

Location: Cogwork Core
Mechanical twins that spin and lash out in sync. Their attacks combine in dangerous patterns, requiring tight dodges. They are mandatory progress in Act 3.

Lace (Second Encounter)

Location: The Cradle
A harder rematch against Lace, with faster flurries and expanded combos. Her laugh is just as obnoxious, but patience and counters after dives still win the fight.

Grand Mother Silk

Location: The Cradle
A late-game weaver matriarch who rains silk attacks across the arena. Defeating her is tied to Hornet’s final trials and the culmination of the weaving storyline.

Last Judge

Location: Blasted Steps
One of the final mandatory bosses. He charges with huge speed, slams to create fire plumes, and throws a thurible that mimics his charge wind-up. Stay patient and punish his recovery for the win.

Optional Bosses and Quest Bosses

Savage Beastfly

Location: Hunter’s March
Charges horizontally and vertically, later summoning adds. Stun it by baiting its charges into walls, then punish during recovery.

Skull Tyrant (First Encounter)

Location: The Marrow
Quest-related. Charges, jumps, and summons falling rocks. Defeating it rewards the Crown Fragment.

Skull Tyrant (Second Encounter)

Location: Moss Grotto, Bone Bottom
Appears as an ambush after turning in the Crown Fragment. Same attacks as before, but staged as a surprise fight.

Moorwing

Location: Greymoor
A giant fly boss. Attacks include downward slashes, dive charges, and claw projectiles that orbit the arena. Can be cheesed from above platforms if approached early.

Moss Mother (Second Encounter)

Location: Weavenest Atla
Two Moss Mothers appear together. Clear one quickly to make the fight manageable. Reward is the Weavelight Tool.

Great Conchflies

Location: Blasted Steps
A swarm-style optional fight against giant Conchflies. Staying mobile and striking during their dive windows is key.

Phantom

Location: Bilewater
Optional spirit fight. Uses spectral attacks and fast dashes. Good for Journal completion.

Unravelled

Location: Whiteward
A strange silk creature that lashes out with unpredictable whip patterns. Optional but dangerous.

First Sinner

Location: The Slab
Optional late-game boss. Uses heavy melee swings and arena-wide crashes. Tied to hidden questlines.

Trobbio (Recurring Rival)

Location: Whispering Vaults (and multiple encounters)
A flamboyant bug rival who uses fireworks and flashy arcs. Fights are optional but repeat as Hornet’s journey continues.

Final Blurb

Hollow Knight Silksong bosses are a mix of story milestones and optional trials, each teaching new lessons in timing, patience, and precision. From Moss Mother’s simple swoops to the towering Last Judge, and side fights like Moorwing or the First Sinner, Pharloom is filled with deadly encounters waiting to be mastered.