Spiked weight

Chain Gates, also referred to as spiked weights,  spiked traps or spike traps, are large spiky logs on chains appearing in Super Mario World 2: Yoshi's Island and its reissue. They typically appear in castles and forts. At the top of a Chain Gate is a wooden wheel with a question mark on it. If a Yoshi hits the pulley with an egg, the gate will rise, allowing the Yoshi to pass under the barrier. Chain Gates cannot be destroyed.

Chain Gates reappear in Yoshi's Island DS. Two of them appear in Yoshi's Island Easter Eggs.

Chain Gates return in Yoshi's New Island, where they are prominently found in Count Fang's Castle.

Trivia

 * In a prototype build of Super Mario World 2: Yoshi's Island, the spiky log of a Chain Gate was originally a shelled enemy with spikes and nails on it.