Wallop

Wallops are enemies that appear in Super Mario 3D Land. They look like Whomps, except they are shaped like a fort wall with black eyes and yellow pupils, with mouths and feet. Instead of attempting to squash Mario and Luigi by slamming on the ground when they get too close, Wallops block the player's way by following their movements. Wallops can also jump whenever Mario jumps and then slam the ground. After jumping, there will be a few seconds in which the Wallop will recover, giving Mario or Luigi a chance to pass by it. When the player is a certain distance away from or behind a Wallop, they will be in a state of dormancy, in which their pupils are not lit and their feet have retreated into their bodies, until the player is in front of them. Mario or Luigi can destroy them by turning into a statue above them or below them when they jump. They make their first appearance in World 3-1; they also appear in World 6-4, World 8-6, Special 3-5, Special 6-1, Special 8-4, and Special 8-Crown.

Trivia

 * Like Whomps, Wallops seem to be inspired by the Japanese, mythological creature nurikabe. Nurikabes block the path of travelers, just like Wallops do.
 * The name Wallop is also a pun on "wall", due to how they look and behave like walls all the time, and the term, "wallop", which means to make a loud crushing noise, or a large attack or beating.
 * By running into a direction and immediately turning the other way, Mario or Luigi can get past the Wallop without jumping.
 * Wallops bare a striking resemblance to the "Blocky" (http://kirby.wikia.com/wiki/Blocky) enemies from the Kirby series.