Ymir

The Ymir is a non-sapient, reptilian humanoid that is native to planet Venus. Virtually nothing is known about the Ymir in its natural habitat, except that it feeds on sulfur and is somehow able to survive in the harsh environment of its home-world.

History
A Ymir egg was found by Human scientists during an expedition to explore Venus and its mineral resources. The egg was brought to Earth to be studied, but unfortunately, the spaceship crashed just off the coast of the Sicily region of Italy. The Ymir egg fell out of the hole in the ship and floated onto the beach of Sicily. After this, a young boy found the egg and eventually gave it to a scientist. When the Ymir hatched and emerged from its egg, it began to grow more and more due to the oxygen-rich atmosphere of Earth. The huge beast started causing chaos and destruction as it searched for sulfur to eat. The alien was eventually killed by Human authorities.

Appearances
 * 20 Million Miles to Earth (1957)

Anatomy
The ymir is a strange animal, possessing scaly, reptilian skin, but being shaped like a primate. It feeds on sulfur, and the oxygen-rich atmosphere of earth, it grows rapidly. It is unclear if it would ever stop growing at all. It appears to be warmblooded, as it remains active during extended periods of time.

Personality
The ymir is driven by instincts and a desire to survive, and like any animal, it is neither good nor evil. It hasn't got any grand schemes of conquering worlds, or,at first, at least, wiping out humanity. Instead, it is driven by a craving for sulfur, and will stop at nothing to find a good meal. It's apitite is insatiable. At birth, it was perfectly safe around humans, as it had grown up around them, but will attack unfamiliar animals. However, when it preyed upon a dog, the owner of said dog retaliated and stabbed the ymir with a pitchfork. Since then, the ymir became misanthropic, and remained violent and fearful of humans. It destroyed buildings and spread havoc, including mauling a zoo elephant to death.