Pre-history

Pre-history is a giant dinosaur created by Timely Comics, now Marvel Comics, from the 1954 comic Human Torch Comics #36.

Name
When originally published, the uncredited writer did not give a true name to the monster, although it is referred to as "The Beast from the Egg" according to the title of the story. It would not have a name until the release of The Saga of the Original Human Torch in 1990 where writer Roy Thomas gave it the name "Pre-history."

History
Pre-history was a perfectly preserved egg of a new species of Tyrannosaur that was discovered in the New Mexico desert. It was engulfed by an atomic bomb that was being tested. It absorbed the radiation, reverting to a non-fossilized state and it rapidly aged the embryo to mature at an astounding rate. After hatching, it grew into enormous size beyond that of a regular dinosaur, and began causing destruction to anything in its path. Those in close proximity to Pre-history was infected and killed by prehistoric germs, killing thousands. With the US military unable to do harm to it, the Human Torch and his sidekick Toro were called in to destroy the monster. Pre-history, however, was not stopped by the two heroes and continued moving west until it reached San Francisco. The Human Torch and Toro forced Pre-history to move into the city's harbor, where the Human Torch commandeered a US Navy submarine and launched a series of torpedoes at the monster's legs, crippling it. Then, the Human Torch and Toro burned away Pre-history's muscles on its lower limbs, where it sunk into the ocean, never to be seen again.

Abilities
Pre-history possessed incredible strength and was able to resist conventional weapons and semi-resisted fire. It absorbed radiation, in which it grew to abnormal size, well beyond any known Tyrannosaur species.

It also was infected by a strain of prehistoric germs that proved to be fatal on humans.

Trivia

 * Pre-history has some notable similarities with Godzilla, which whom it predates. Both were created in 1954 (with Pre-history premiering in April and Godzilla in November), both are giant dinosaur-like monsters, both attacked a major city, and both had origins tied to atomic bombs.