To make an elf on a shelf bendable, you can start by making the body out of bendable plastic or rubber. Then, you can add joints to the arms, legs, and head so that the elf can be positioned in various poses. To add extra detail, you can paint the elf's face and clothes and add accessories like hats or scarves. Finally, you can add a small hanger to the back so the elf can be displayed on a shelf or Christmas tree.