Biology[]
The Screaming Death appears to be a heavily mutated, albino Whispering Death. It is white in color, has large red eyes, a longer and a more massive body and larger tail than a normal Whispering Death. It also has three rows of teeth, but they are aligned differently than those of the Whispering Death, set in a chin reminiscent of the Seadragonus Giganticus Maximus. Despite the Screaming Death's is size, its wings are only the size of Toothless's.This is because it uses its excessively long tail as a sort of rotor. The size of Screaming Death is said to be 70meters long. It is possible that they will grow even bigger.
It has powerful large jaws with surprisingly strong jaw strength that can be used to bite at close range. And it is also shown to be large enough to fit a female Gronckle and not a smaller rider inside.
Judging by the massive size of what is apparently a hatchling, this albino giant is probably one of the biggest dragons of them all. The Screaming Death is attracted to light as opposed to having an aversion (only for young dragons), as the Whispering Deaths do. It also differs from the Whispering Death as its' tunnels are so large that they can cause islands to sink. The scales of the beast are extremely tough, as it is not phased by being hit with theDeadly Nadders' spines. The Screaming Death is also able to plow right through massive sea stacks with ease, just like the Green Death. The Screaming Death also seems to have a mutated maturity cycle and seems to become a full grown adult faster. There is only one in the show so its maturity level is not fully known either.
The Screaming Death is relatively intelligent, as it did not fall for the refection off Hiccup's shield a second time. Seemingly, the dragon succeeded to overcome some of weaknesses unique to the main species through mutation. The Screaming Death is attracted to bright and intense light, unlike the Whispering Death.
The Screaming Death's egg resembles a Whispering Death's egg, but larger in size and colored red. Either the Outcasts were extremely stupid and didn't register that one of their own eggs was much bigger to begin with, the Screaming Death had been on Berk all along and would only hatch if there were more Whispering Deaths present than had previously been available, the egg somehow grew by itself, or the hundred years by sheer coincidence happened to be up when the Whispering Death eggs hatched.