A fictional Alien Walker (Robot) mecha from the novel "The War Of The Worlds" published in 1898.
It is a giant three legged Robot piloted by a Martian and armed with a devastating energy cannon (the "heat ray") and several mechanical tentacles. This machine is perhaps the first example of an alien Mecha in the Science Fiction genre.
The Big Zam from Mobile Suit Gundam was inspired by this walker.