The 地下墓穴 is a decorative item that can be placed on background 牆 in a manner similar to a 噴漆. It resembles a rectangular pit in the wall with a skeleton resting inside (as if it were a catacomb). The Catacomb can appear with one of three different frame styles, and one of three different skeleton positions. Catacombs can be found on the walls deep within a 地牢 with tiled walls.
- There is only one Catacomb item. Its configuration (frame type and orientation) is determined at random when it is placed, and persists even through reloading the game. Breaking and then placing the Catacomb again will change the configuration.
- Some configurations may make it seem like the Catacomb is only two blocks high (or at least very close), even though the actual height will always be three blocks.
- Despite the mechanical similarity, the Catacomb is not actually considered a painting in the game's code. This is most likely because it has a different look, both picture and the frame, each time it is placed. Another difference shown in-game is that when viewing objects on the 小地圖, any painting will say "Painting" in the tooltip, and the Catacomb will read "Catacomb".