Some of Laika’s stop-motion puppets have muscles that flex as their arms are animated.

Adam Savage shared a captivating half hour video of him exploring many of the detailed stop-motion puppets Laika Studios created for its new animated film, Wildwood. The studio’s animators already revealed that their puppets now have internal diaphragm’s making them appear to breath, but several of the puppets also have hidden mechanisms in their arms making biceps automatically flex as they’re moved. [Media: https://www.youtube.com/watch?v=9stm18DFD08]