A giant creature of unknown origin that lived in a mine in Blind Rock, Wyoming, the original Silver Hydra turned a group of miners into silver statues fifty years ago. Now, in the modern age, the mine has long since been shut down, but that didn’t stop two brothers from venturing inside with their little sister waiting patiently outside. In the nearby town, H.E.A.T. heard of the legend and decided to take a look where they found the little girl and the brothers, almost entirely encased in silver, inside.
Elsie and Nick had a run in with one of the creatures and it also managed to spit its silver on Elsie’s leg. The silver quickly began to harden and spread, but Nick managed to get them to safety. Upon meeting up with the others, the creature attacked again, but Craven sliced it to bits with his newly created hand held laser.
This was a mistake as instead of dying, each piece regenerated into a new hydra! To make matters worse, Monique, whom was watching Meg, the little sister of the two brothers, had to chase after the girl whom also entered the mine to help. They came across one of the creatures and despite taking a ride on one of the mine carts, it refused to stop.
Meanwhile, as the other Silver Hydras formed an army, the mine ceiling gave way and Godzilla emerged, ready to protect his friends. The hydras blasted the giant reptile with their silver, coating his chest in the material before he unleashed his atomic fire, blasting the hydras into the wall where they splattered. The pools that formed quickly began to turn into one and absorb the elements within the wall and ground, and the giant Silver Hydra was born.
Only one miniature hydra was left, and that one would be put down as well. Running across Nick and the rest of H.E.A.T., Monique and Meg accidentally led the one chasing them to the others. However, the group had a plan to flood the mine with freezing water, and once that water came, it washed the last, smaller-sized Silver Hydra away where its body quickly hardened and shattered.
After being blasted by Godzilla, the miniature Silver Hydras began to merge into one powerful entity. Roaring loudly, it quickly sprayed Godzilla with more of its liquid metal. Unable to free himself from it, Godzilla was helpless as it spread over his body, encasing him in a silver cocoon. However, thanks to H.E.A.T. opening up a hole in the wall and allowing the freezing water of an underground spring flow through, the silver shattered, freeing the reptile and also washing the giant Silver Hydra away. It tried to get to safety, clinging to a large rock, but Godzilla burst from the water and grabbed it and pulled it down. Its body, unable to cope with the icy water, hardened and then shattered, ending the legend of the Blind Rock.
- The miniature Silver Hydras can each fire two streams of liquid silver from each side of their face. When hitting an object, the silver will not only begin to solidify, but also spread, covering a much larger area then originally hit.
- Under extreme circumstances, the miniature Silver Hydras can merge together to form one massive, two-headed creature.
- The miniature Silver Hydras are capable of re-growing into more creatures if they are somehow cut to pieces.
- In order to grow into one massive Silver Hydra, the miniature versions must absorb minerals from the area around itself, possibly other sources of silver.
- The Silver Hydras will solidify and shatter if exposed to a cold source for too long.
- The Silver Hydra is named after the mythical multi-headed serpent who grew two heads if one was severed (this is referenced by the two-headed combined form of the creature).
- The Silver Hydra may be inspired by Dogora.
- The Silver Hydra is officially the first Kaiju in the animated series to have killed humans, having absorbed a group of miners years ago. Randy Hernandez and Mendel Craven would later discover it's victims' remains, their corpses trapped within the silver shells.