scamperer

/ˈskæmpərər/
noun
  1. A person or animal that runs quickly and playfully, especially in short bursts.
    • As a child, she was a notorious scamperer, always racing through the hallways.
    • The puppy was a happy scamperer, dashing across the lawn after every butterfly.
    • The squirrel, a nimble scamperer, darted up the tree trunk in seconds.