In the words of the creator:
The Trident of Might is only use able by Magus. When equipped it can do one of three things: 1) 80% chance-dose normal attack. 2) 19% chance-will hit for 9,999 damage, while poisoning, and confusing the enemy. 3) 1% chance-kills one enemy, even if it's a boss, and either kills the Trident holder or confuses every one in the party. It is found by taking the item "rare rock" to the blacksmith who was at the millennial fair.
A pretty well-balanced weapon. It does 80% of the time a regular, no-frills attack. Sometimes it'll hit for a nice maximum of damage while poisoning and confusing. But the last, 1% of the time event: kills an enemy in one hit BUT kills the trident holder or confuses the whole party.