The in-game name is Strange Silver Etched Skull. They are small, often hidden on rooftops or behind secret walls, and the game never tells you how many you have found or how many exist. That has frustrated a lot of players: PovKetz on Steam said they had "maybe 50+" but had lost count.
How many Silver Skulls are there?
69. Three sources agree: Steam user bb, Digitol's 100% guide, and Sdaknight's Chinese 100% guide, which says the last reward comes after handing in all 69.
Because there is no counter, Digitol recommends taking a screenshot or a note each time you pick some up.
Where do you turn them in?
Skulls are handed in for rewards as you go. Steam user thoughtlostme mentions getting four "trinket rewards" from turning in skulls. Zer0's guide refers to a "Skull NPC", and thoughtlostme reports that one area in the Ancient City hills only became reachable after the third reward.
All 69 matter for Ending 4. Bb says the place that accepts them is in the Petrified Garden, and Sdaknight writes that once all 69 are handed in, you go through an underground gate. See Endings for the rest of the Ending 4 requirements.
Exactly who or what accepts the skulls, and what each reward is, is not clearly described in our sources, so the details are to be confirmed.
Where are the skulls on the Isle of Neasied?
From Zer0's list unless noted:
- On top of the cook's chimney in the starting zone, and another on a far island past that chimney
- On a broken pillar near the pyramid brazier
- In a broken crevice of one of the blue-flame pyramids near the teleporter
- In a pot inside the cook's place
Where are the skulls in Obmuer Temple?
- On the lift just past Dagoom's door. SquidRadio counts this as skull #1; Digitol also mentions a skull beneath the elevator after the boss
- Top right of the room with the three royal guard mini-bosses (Zer0)
- On the temple island close to the starting island (Zer0)
- Dash from Obmuer's Wind Gem gazebo, roughly north; Zer0 says it takes a lot of dashes
Where are the skulls in the Tower of Knowledge?
- Basement, top right corner near two gargoyle crossbowmen (Zer0). Sdaknight places one above a stone pipe where you first meet three gargoyle statues after the trap door
- Behind a hidden wall reached from the trap-door room's stairs, then down a hole into the basement, behind a statue on the left (Deer God.)
- On top of the Tower, which needs flight; outside on an upper floor past the gravestones; above the doorway to the bridge to the Mausoleum (Zer0)
- On top of one of the towers on the bridge between the Tower and the Mausoleum (Zer0); SquidRadio also finds one on a tower roof of that bridge
- On the elevator between the Tower and the Forgotten Dungeon: a round room at the bottom with three green torches and a skull near the ceiling (Zer0)
Where are the skulls in the Deimpo Mausoleum?
All from Zer0's list:
- On the staircase where you meet the first spider, behind a double secret wall
- At the back right of the Mausoleum's exterior
- In an open sarcophagus behind the secret wall next to the bat orb statue
- High up in the huge room with the moving blocks
- In the Mausoleum boss room
- In the shafts and vents between the Mausoleum and the Ancient World (two)
Where are the skulls in later areas?
Zer0 lists many more, spoilers for late areas:
- Ancient World: high up by a skyscraper facing the castle, in the Electric Rifle tunnel with the laser eyes, on several skyscraper roofs, on hills, above the 5th Wind Gem gazebo, near the teleporter by dropping into a hollow tree, and before the drop into the Record of Sin. See Ancient World.
- Siraatsu Castle: in the basements, the junkyard area, high in the main hall, on the castle roof (Zer0 thinks there are two), and on a container in the storage room behind the bar.
- Verdant Hollow: where you get the true holy sword, on a branch reached from the Mausoleum's secret staircase, on the building with the sealed Siraatsu statue door, and several more.
- Rotting Cavern: high up near the teleporter, and three high up near the gates between the Petrified Garden and Verdant Hollow.
- Forgotten Dungeon: on a pillar in the Skeleton Witch's boss room, on a ledge at the top, in the cave at its entrance, behind the throne where you place the mementos, and on a dark elevator.
- Record of Sin: in the boss room, with Zer0 guessing two or three more on the tower floors.
Any tips for finding the last few?
- PovKetz noticed that a hidden wall with an obvious hint (a pointing skeleton, vines) is not highlighted by the lenses, so search those by hand.
- Digitol suggests using the Mask of Second Sight on stone faces, alcoves and apparent dead ends, and checking high platforms with all your dashes.
- Revisit areas after each skull reward, since thoughtlostme found at least one skull that needed one.