User blog comment:Dragonking99/Who will win: Screaming Death vs Red Death/@comment-3230751-20131122225336

The Red Death was able to keep up with Toothless in flight, so I don't think his speed is 5. Toothless has been shown to be able to outfly the Screaming Death without much difficulty, so I also doubt that its speed is 18.

Also, even after having grown, the Screaming death is only about half the size of the Red Death. You can look at Toothless as he falls and the Red Death chases him, and in one shot it becomes obvious how big Toothless is compared to the Red Death's head. Then look at the shot in Appetite for destruction with Toothless facing down the screaming death, and you can tell that the boulder class monstrousity is much smaller than the Red Death,

Finally, bulk. The Red Death is one huge mountain of muscle while the Screaming death is relatively long and thin. I imagine that if the Red Death got a hold of the Screaming Death's body in his jaw that he could do serious, serious damage.

Also, note that the wild dragons were not afraid to attack the Screaming Death while fear kept them in line with the Red Death. Why? The Red Death was much deadlier.

So, in the end, Red Death would win. I mean, Hiccup and Toothless have been able to outdo the Screaming Death twice without being defeated, while when they fought the Red Death, Hiccup lost his foot.