Bone

The  is a melee weapon that has a special followup attack when successfully striking the enemy with the second attack in its combo.

Location
Found in a lore room in Prisoner's Quarters that contains a single interactable pile of skulls. Interacting with the object drops the weapon rather than just a blueprint, and equipping the weapon automatically unlocks it to be used in later runs.

Trivia

 * This weapon was added as part of the crossover event with other Indie games for the "Everyone is Here" Update. It is directly inspired by the starting weapon of the protagonist and namesake of the game Skul: The Hero Slayer.