The Mound: Omen of Cthulhu Guide | How Extra Knives and Rank Rewards Work

Here’s a guide on how Extra Knives and Rank Rewards work in The Mound: Omen of Cthulhu.

Game Guide by Jubair Baky on Jul 30, 2026

The “Extra Knife” Rank Reward in The Mound: Omen of Cthulhu is easy to misunderstand because it does not add another knife to your inventory. It unlocks a new cosmetic appearance for the Sailor’s Knife. Rank progression also grants practical upgrades such as inventory slots, stronger revives, Weapon Grip Bonuses, and the Ring of Isolation Resistance.

The Mound Omen of Cthulhu Guide How Extra Knives and Level Rewards Work

You still receive one Sailor’s Knife for your explorer. An Extra Knife reward adds another knife design that can be selected from the knife cupboards beside the Armoury. The cosmetic changes the weapon’s appearance but does not provide another usable knife, an extra attack, or an additional inventory slot.

How to Equip Extra Knife Cosmetics

Return to the galleon and inspect the knife cupboards beside the Armoury. The available designs include appearances earned through Rank Rewards, along with any eligible edition or account bonuses. Select the design you want, then collect the Sailor’s Knife when preparing for an expedition.

The Mound Omen of Cthulhu Guide How to Equip Extra Knife

Check Rank Rewards in the Guidebook

Open the Guidebook and select Rank and Experience to review the progression rewards. Completing expeditions earns XP and increases your Rank. The clearly identified milestones include an Extra Knife at Rank 2, an Extra Inventory Slot at Rank 4, improved ally revival health at Rank 10, another Extra Knife at Rank 12, and a 15% Weapon Grip Bonus at Rank 14.

The Mound Omen of Cthulhu Guide Check Rank Rewards in the Guidebook

Higher-Rank Reward Milestones

Rank 16 grants another Extra Knife, while Rank 18 adds another Extra Inventory Slot. Rank 22 improves the health restored when reviving allies again. Rank 24 grants another knife appearance, Rank 26 increases the Weapon Grip Bonus to 30%, and Rank 28 unlocks another Extra Knife. Rank 30 currently grants the Ring of Isolation Resistance, which helps reduce the danger caused by remaining too far from teammates.

Extra Knife rewards unlock Sailor’s Knife cosmetics, while the other Rank Rewards provide permanent progression bonuses.

Weapon Grip Bonuses make it less likely that tentacle attacks will pull a held weapon from your hands. The Ring of Isolation Resistance is especially useful in co-op expeditions, where extended separation can trigger isolation effects and attract threats that target isolated explorers.