A trident is a three-pronged pole arm; its name literally means "three teeth". It is used as a regular spear but has three points to triple the damage it would do to an opponent. Also, a trident can catch a weapon and send it off to the side, whereas a spear can only parry.
The trident was almost the only weapon used by toads throughout the series, making it one of the few weapons that is used by an entire species (though toad archers are mentioned in Salamandastron). The trident was also used by Ublaz Mad Eyes's special force, the Trident-rats, led by Sagitar Sawfang. In addition, Ungatt Trunn used a massive trident in his hand-to-hand combat with Brocktree, and the Wearet Kharanjul used one against Bragoon and Sarobando in the Battle of The Abyss. Furthermore, Captain Razzid Wearat owned a barbed trident, which was also his standard (in The Rogue Crew, the image of a trident with eyes was referred to as "The Sign of the Wearat").