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From Pathfinder Lost Omens The Grand Bazaar, which isn't enabled.

Dragon's Crest

ITEM 1
Price 10 gp
Usage held in 1 hand
Bulk —
Category martial
Group shield
Damage 1d6 bludgeoning

This variant on the shield boss is usually shaped like a dragon's head, its jaws open wide enough to wedge a small vessel of liquid within. A dragon's crest can be etched with weapon runes, much like a shield boss or shield spikes, but doesn't otherwise alter your shield's statistics. A shield bearing a dragon's crest can't be combined with an attached weapon, like shield spikes.

You can use an Interact action to wedge an alchemical bomb into the crest's jaws. While a bomb is wedged in the shield, you take a -1 penalty to attack rolls with the shield. When you successfully Strike a creature with the shield, the vessel shatters, exposing the creature you hit-and yourself-to the substance within. This counts as a successful hit with the bomb against the creature if it's adjacent to you or a successful hit against the appropriate adjacent square if it's not. The bomb deals splash damage as normal to surrounding creatures, including you. In addition, the bomb deals full damage to the attached shield.

Pathfinder Lost Omens The Grand BazaarOGL