When alive, the ribcage, is dark purple with curved lines on either side as the "ribs". There are three shooters at its front which are made up of two layers. Dark spots can be seen between each shooter.
When dead, the ribcage loses its shooters and becomes grey and white in colour. A picture of a torch can be seen upright to the player's perspective, with a dotted orange line trailing off from the top of the torch.
The ribcage begins to attack when just out of range from the young seedling. As he approaches, the ribcage shoots three bullets, one from each of its shooters. The ribcage remains stationary for the entire duration of the game, but pivots to face the young seedling so it can attack.
With the sword, the young seedling has to attack it while avoiding the bullets shot by the ribcage. In Lacste, a block can be used to shield the young seedling from the ribcage's attacks while allowing him to get close to it so he can attack more easily.
When the ribcage is defeated in Lacste, it becomes smaller in size and more pale. The player can now use the dead ribcage like a red block, using the Fire powerup to move it up to the switch. Since there is only one red block present in the area, the player needs to push the dead ribcage up so it holds the switch, keeping the locks open. The young seedling can then move the red block to the switches farthest to the right to open up the pathway that will allow him to proceed to the next area.
The ribcage also makes an appearance in Ghethis, just outside the entrance to the main Ghethis area. It shoots at the young seedling amongst some squids who move in to attack him. Like the one in Lacste, the player can slay the ribcage by hitting it with their Ghost Spear, but when killed, the ribcage disintegrates rather than turning into a movable block like it did in Lacste.