Fallout 4 secrets continue to be uncovered. The latest example is a harpoon-style gun that a modder discovered when rooting through the RPG’s files. The animations look a little dodgy, suggesting this gun was not meant to be discovered, at least not yet.

Modder xxdeathknight72xx (via Kotaku) found the weapon, which replaces the Railway Gun if you have it in your arsenal. Interestingly, a bubble animation surroundings kill, suggesting Bethesda might have envisioned an underwater sequence in Fallout 4. The video’s host, Tryannicon, also surmises that it’s possible this weapon may be featured in Fallout 4’s upcoming DLC and wasn’t mean to be found just yet.

Details on the necessary mods to unlock the Fallout 4 harpoon weapon in the PC version of the game are available here on Nexusmods. Fallout: New Vegas featured an underwater segment, but there wasn’t any combat in it.

Before this, Fallout 4 players discovered the game’s developer room, which features every item in the game, including all weapons, armor, and more

Fallout 4 launched on November 10 across PlayStation 4, Xbox One, and PC. Bethesda shipped 12 million copies to retailers on launch day, though it’s unclear how many have actually been sold through to consumers. Whatever the case, Fallout 4 is clearly very popular, having broken Steam concurrent player records.

The first of Fallout 4’s patches arrives next week in beta for PC. In other news, people are dressing up cats in Fallout clothing, while this parody video explains how Fallout 4 is ruining lives. Players have also created characters based on Taylor Swift, Kanye West, and Louis C.K.