The Moving Crates are large moving blocks embedded in walls. They possess an artificial intelligence that compels them to exile anyone they see and a very sensitive sensor which detects those in front of them.
In gameplay, the Moving Crate is a very dangerous obstacle. Always located in enclosed 2.5D sections, they will move out from the walls behind Sonic and push him forward. While they sometimes move Sonic along the path or act as crushers, they can also push him towards the screen which will make Sonic fall off the path and into a bottomless pit. Because they are too tall to be jumped over and are found in enclosed spaces, the Moving Crates are almost impossible to avoid once they start moving.
In the Xbox 360/PlayStation 3 version of Sonic Unleashed, the Moving Crates have faces resembling that of Dr. Eggman. They are only encountered in Eggmanland. In gameplay, when they sense Sonic in front of them, they will smile and glow purple before starting to move.
In the Wii version of Sonic Colors and the remaster Sonic Colors: Ultimate, the Movable Craters are more simple grey blocks aligned with straight lines of lights. They appear in both Asteroid Coaster and Starlight Carnival. In gameplay, when they sense Sonic in front of them, their lights will flash red before they start to move.
In other media
Books and comings
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics, the Moving Crates appeared in Sonic Universe #84. Here, Thunderbolt the Chinchilla was almost crushed by two of them on her way inside a refinery, but she held them back thanks to her new suit. In this media, they resemble the ones from Sonic Unleashed.