The trident of the swamp (e) (also called the toxic trident) is an enhanced staffthat requires 75 Magic to wield. It is an enhanced version of the regular trident of the swamp obtained by giving Lieve McCracken 10 kraken tentacles, costing 9,581,760. It holds 20,000 charges, rather than the 2,500 charges of the unenchanted version.
It is tradeable only when uncharged. The fang can be removed from the trident only when it is uncharged. The built-in spell cannot be used against players outside of the Castle Wars and TzHaar Fight Pit minigames, as well as the Clan Wars minigame if the clan leaders enable it. The trident cannot be used to autocast any other combat spells. Similarly, the trident of the swamp and seas both do not reward a base experience for each cast. Instead, players are rewarded experience for each point of damage dealt. The experience gained is 2 experience points per damage dealt.
The enhanced trident can hold up 20,000 charges when fully charged. Charging the staff requires 1 death rune, 1 chaos rune, 5 fire runes and 1 Zulrah's scalesper cast, costing 10,860,000 coins to fully charge it, and 570 per cast. Trident charges can be removed at anytime to recover the runes and scales.
The toxic trident has increased bonuses, provided it is charged with Zulrah's scales. In addition, players using combat spells when wielding the trident have a 25% chance of inflicting venom on their opponent.
In addition, the trident of the swamp has increased base damage by 3, meaning it has 3 higher max damage than the regular trident of the seas. This would put the max hit of the swamp trident at 34 with the occult necklace, 35 with an occult and a boosted magic level, and 41 with the aforementioned equipment/boosts as well as a tormented bracelet and an imbued slayer helmet on a task. The maximum hit can be increased even further by using an imbued heart instead of magic potions resulting in a max hit of 44.
If a player dies with the trident, any scales that were used to charge it will appear on the floor along with the uncharged trident (only if it's not protected on death).
copied from old school runescape wiki
tl;dr 10 kraken tents is given to a npc to be able to charge ur trident of the swamp 20k charges instead of 2,5k