The only mammal that cannot jump is the elephant. Elephants are large, heavy animals, and their body structure is not designed for jumping. Their legs are straight and pillar-like, which provides the necessary support for their massive bodies but limits their ability to leap off the ground.
Unlike other mammals, elephants lack the flexible joints and spring-like tendons that are essential for jumping. Additionally, their weight makes it nearly impossible for them to lift all four feet off the ground simultaneously. This unique characteristic sets elephants apart from other mammals, making them the only ones that cannot jump.