supertux/data/images/objects/unstable_tile/castleblock.sprite

(supertux-sprite
  (action
    (name "normal")
    (images 
      "castleblock-0.png"
    )
  )
  (action
    (name "shake")
    (fps 8)
    (images 
      "castleblock-0.png"
      "castleblock-1.png"
      "castleblock-2.png"
      "castleblock-3.png"
    )
  )
  (action
    (name "fall-down")
    (fps 1)
    (images 
      "castleblock-3.png"
    )
  )
)