Onyx Excavator Key

The Onyx Excavator Key is a Pre-Hardmode mount summoning item obtained from the Cavern shrine. When used, it summons an Onyx Excavator which acts similarly to the Basilisk summoned by the Ancient Horn but allows the player to drill through almost all blocks in the game. Like the Basilisk, it can charge enemies and deals 25 damage upon contact. This damage can be boosted through summoner bonuses.

The Onyx Excavator is capable of moving and digging at a speed of 40 mph horizontally and can jump a single block off the ground.

Standing next to blocks and holding the "use" button causes it to mine out most of the blocks on either side of it, and allowing you to use the item you're holding as normal.

While moving, the player's damage reduction is increased by 10%. This is calculated independently from normal DR and is not affected by Calamity's DR scaling system. Additionally, all fall damage the player takes while inside the excavator is reduced to 5, increased to 10 in hardmode.

The Onyx Excavator can only dig to the sides. It cannot dig vertically.

Trivia

 * The mount is a reference to the Acceleration Drill from the Avalon Mod, with both digging through tiles in a similar way.
 * The tooltip references PETA and EPA, both being real companies which aim to protect animals and the environment respectively.