Super Mario World/Enemies/Thwomp

Thwomps are rectangular anthropomorphic stones that bounce up and down every once in a while (often every other second). They appear only in castles and fortresses. The best way to get past them is to simply dodge them.

Resistance to attacks

 * Normal Jump: Mario/Luigi is harmed.
 * Spin Jump: No effect.
 * Jump with Yoshi: Yoshi is not allowed in castles or fortresses.
 * Fireballs: No effect.
 * Yoshi's Tongue: See "Jump with Yoshi".
 * Yoshi's Fireballs: See "Jump with Yoshi".
 * Sliding down a hill: Impossible, because there are no hills in castles or fortresses in the game, other than escalators, which only move upward.

Locations
All castles and fortresses, including Bowser's Castle.