Blockstepper

Blocksteppers are enemies first appearing in Super Mario 3D World. They are red blocks with feet and -like mouths. They also wear brown soldier hats and have wind-up keys in their backs. Their name is a combination of "block", which they resemble, and "lockstep", referring to their synchronized marching formation.

Blocksteppers appear in various levels, always marching back and forth (forward in autoscrolling levels) in groups of two or more. They can be defeated with any attack, but defeating one from the group will scatter the group and cause them run around frantically in panic. After a few seconds, they will act in unison and angrily chase after the player.

Trivia

 * Blocksteppers make a very similar sound to a Pikmin when they are undisturbed and chanting.