Slayer Codex

A Slayer Codex can be used to track all the slayer monsters killed. It is given to the player by Faiza. Obtaining the codex requires 99 Slayer. Creatures are added to the book through ushabti after taking captured souls to the Chest of Souls.

The first ushabti of a creature that the player turns in gives them full experience, and the following ushabti of that same creature gives the player 25% experience. Turning in all souls at least once will complete Slayer Codex, which will give cumulative Slayer experience equal to 1,442,875 experience.

After collecting the souls of 50 different monsters, the codex can also teleport players to the Sunken Pyramid.

Slayer monsters
In order to fill the entire codex, players will need 117 Slayer (boostable) and 115 Dungeoneering (which cannot be boosted). This does not include other requirements such as quests and tasks. Some monsters can only be killed while on their respective slayer task.

For monsters that fall under one category, killing any non-boss monster will be eligible for the ushabti to capture its soul. The only exception to this are gemstone dragons, corrupted creatures and soul devourers.

Trivia

 * TzHaar and Volcanic creatures are the only slayer categories not included in the codex in any form.
 * Gemstone dragons, corrupted creatures and soul devourers are also not included as categories of their own, as each monster belonging to them has been separated into their own category for the purposes of the codex.
 * A boosted Slayer level does not count towards the likelihood of getting a soul.