Which animal carries its house everywhere it goes?

I run all the time, but never move a foot. I have a mouth, but never make a sound. What am I? Solve the riddle → I play music and voices but have no voice of my own. What am I? Solve the riddle → You climb up my stairs, and then you zoom down so fast! I stand in the park, and my fun never ends. Solve the riddle → Which animal carries a sword but never fights? Solve the riddle → I have legs but cannot walk. I have a flat back where things often rest. Solve the riddle →