The larva builds a pupal chamber, a room for the pupa, and as it turns yellow, it first hardens its legs to form a pupa. The larva can still move its abdomen after pupation.
Many insects pupate in order to undergo metamorphosis. During the pupal stage, the body undergoes a major transformation. The body of the adult insect is built using nutrients stored in the larval stage. The interior of the pupa becomes a sludge of dissolved nutrients from the larval body, and an organ called the adult protoplasm is transformed into wings, legs, and other body parts.

The contrast difference is even less than in the larva, and in addition to a slight structure reminiscent of an adult, the shape of the ducts extending from the stomatophora can be seen.
The ducts that used to run throughout the body have changed shape significantly since the larval stage, extending all the way to the tip of the antler.
This CT image was taken of an individual about two rounds after it changed from larva to pupa, but it is expected that this internal condition of the body also changes significantly during the pupal period.