This item looks like a normal trident carved with Gozren motifs.
Category
Wondrous consumable
Level
9
Price
110 gp
Usage
held in 1 hand
Bulk
L
Activate
2 actions (concentrate, manipulate) An item with the expandable trait increases to a specific size when activated. Unless otherwise noted, this space must be adjacent to you and on the ground, and the item needs to have enough open space to expand into or else the activation has no effect. When the effect ends, the expanded item disintegrates if it's a consumable or shrinks back to its normal size if it's not a consumable.
Traits
Consumable, Electricity, Magical
This item looks like a normal trident carved with Gozren motifs. If thrown without being activated, it wobbles in the air and fails to strike true. When you Activate the trident, the carvings crackle with electricity. You then hurl the trident. It shatters immediately after leaving your hand and unleashes its magic as a 4th-rank lightning bolt originating from your space. The bolt deals 5d12 electricity damage and has a basic Reflex save DC of 25.
Craft requirements
Supply a casting of lightning bolt (4th rank).
Traits
Consumable
Electricity
Magical
Source: Pathfinder GM Core, p. 269
Bring Trident of Lightning into a Pathfinder 2e game with The DM Screen.