This item is a educational construction kit assembled from various materials (plastic, metal, etc.). Cement is required, but no painting is necessary.
Gakken's "Mechamo Series" of kits are more complex than kits intended for younger hobbyists (though of course with adult supervision, there's no reason a bright youngster can't put them together!). This metal crab will skitter in a very -- well, crab-like! -- manner, when completed. Everything you need to build it is included in the box; requires 6 AA batteries, not included. Download the parts list and the English instructions (both are PDF files. If you don't have Adobe Reader, download it for free!)