The sound came from a glistening metal machine which stood half-hidden in the brush a dozen yards away looking at him!

The thing was made of a lustrous, silvery metal, which Dan afterwards supposed to be aluminum, or some alloy of that metal. Its gleaming case was shaped more like a coffin, or an Egyptian mummy-case, than any other object with which he was familiar, though rather larger than either.

That is, it was an oblong metal box, tapering toward the ends, with the greatest width forward of the middle. Twin tubes projected from the end of it, lenses in them glistening like eyes. Just below them sprang out steely, glistening tentacles several feet long, writhing and twitching as if they were alive. The tangle of green brush hid the thing's legs, so that Dan could not see them.

Suddenly it sprang toward him, rising ten feet high and covering half the distance between them. It alighted easily upon the two long, jointed metal limbs upon which it had leapt, and continued to keep the lens-tubes turned toward Dan, so he knew that the grotesque metal thing was watching him.

The limbs, he observed, were similar to the hind legs of a grasshopper, both in shape and position. And evidently the thing leapt upon them in about the same way...

For several minutes the two stood there, studying each other. A naked man, tense and bewildered in the presence of mysterious forces—and a grotesque machine, cased in gleaming white metal, whose parts seemed to duplicate most of the functions of a living creature.

Then one of the writhing tentacles that shot from the "head" of the machine reached back under the metal case, and reappeared grasping what appeared to be a flat disk of emerald, two inches across and half an inch thick.

This green disk it held up, with a flat side toward Dan. There was no sound, but a flash of green light came from it, cutting a wide swath into the jungle, and littering its path with smoking and flaming debris.

But Dan, expecting something of the kind, had flung himself sidewise into the shelter of the boulder beside which he had slept. Behind it, he gathered his feet under him, picked up a rock of convenient size for throwing, and waited, ready and alert.

(Metal Monster from 'The Doom From Planet 4' by Jack Williamson)

He heard the soft humming sound on the other side of the boulder. A[11] glittering object flashed above him. Crashing through the brush the metal monster came to earth on the same side of the boulder with him.