The Karamthulhu is an unreleased pet that could have been obtained as a reward from Rum Deal. It had "Take", "Talk-To", and "Dismiss" options. For unknown reasons, the pet was scrapped before launch.
It has never been obtainable in Old School RuneScape. Although the item remains in the game files, the NPC has since been removed.
- There was previously a glitch where if a player died with a regular Karamthulhu in their inventory, the pet would appear where they died and walk around for a while before despawning.