When equipped, the Shadow Thurible will attract and ally the Reanimated Skeleton to the holder. It has a durability of 9 minutes and can be refueled with Nightmare Fuel for 33% durability, allowing it to last 3 more minutes for each Nightmare Fuel added.
The Shadow Thurible can be used on the Surface and Cave variants of the Reanimated Skeleton and does not have any effect on the Ancient Fuelweaver.
If the Caves Reanimated Skeleton is attracted by the Shadow Thurible, it will still be hostile to other entities, including other player characters.
On the surface, the Forest Skeleton can be brought right next to the players so they don't have to be followed to pick their resources.
In the caves, the Caves Skeleton can be brought with the player to attack enemies, as it deals a large amount of damage.
Character quotes contradict each other: Wilson states it smells like chemicals, Willow states it smells like burnt hair, Maxwell states it smells like roses, and Winona states that it smells like gasoline. This means that the smell of the Thurible depends on the person, possibly being based off of what they want, or possibly fear.