The cavern key is an item obtained during the Creature of Fenkenstrain quest. It is obtained by killing a level 51 wolf-woman Experiment in the Experiment Cave. There is also an extremely small chance the other experiments can drop the key. It is required to unlock the door to the Mausoleum, which is located in the north-west passage of the cave.
If the player is already carrying a key or has completed the quest, they cannot attack another wolf-woman Experiment. Attempting to do so results in the message 'You don't have the heart to kill the poor creature again.'
After the quest, the key can be obtained from the chest in the northern part of the Experiment Cave, near the ladder to the Mausoleum.
This key cannot be put on the Steel key ring.
Monster Combat level Quantity Rarity Experiment 51 1