MUTO stands for "Massive Unidentified Terrestrial Organism." MUTOs represented as a specific alien species in the 2014 film, Godzilla

General description:
The MUTO's bodies are covered in an iridescent, metallic grayish-black exoskeleton. They have orangey-red, narrowly shaped eyes. The shape of their head is reminiscent of Gyaos, and they have triangular jaws resembling a hooked beak.
Both males and females possess long, slender, somewhat deer-like hind limbs, with flat, broad feet ending in two hoof-like toes. The forelimbs all end in a pseudo claw form, being curved like a sickle. When walking the MUTOs use the front "knuckle" of their claws, giving it a hook-like appearance.

As represented in Godzilla, MUTOs are sexually dimorphic.

-Female MUTOs have two pairs of forelimbs and a smaller pair on their abdomen, and is much bigger than male MUTOs, standing nearly twice the height of a male.

-Male MUTOs are similar in appearance, except that they're much smaller in size and appear more nimble. One of the two forelimb pairs has been modified into wings, which are long, pointed and membranous