From Pathfinder Treasure Vault (Remastered), which isn't enabled.

Collar of the Shifting Spider

ITEM 5

Price 133 gp

Usage worn collar

Bulk 1

This intimidating collar contains a hollow central tube and ends in twin metal points shaped like spider fangs. The collar can be loaded with an alchemical mutagen as an Interact action.

Activate (manipulate)

Trigger You roll initiative

Requirements A mutagen is loaded in the collar

Effect The metal points dig into your neck, inflicting 1 piercing damage and injecting the mutagen directly into your bloodstream. This has the same effect as if you drank the mutagen conventionally, except the duration of the mutagen is halved due to the more direct administration.

Pathfinder Treasure Vault (Remastered)ORC