Though few are aware of the fact, velociraptors were actually the first species chosen by Sauron for the elite steeds of the Nine Nazgul, due to their exceptional speed and ferocity in combat. However, due to a clerical error in translating Sauron’s instructions into Black Speech, the project supervisors were led to believe that these “raptors,” like the birds of prey, also somehow possessed the ability to fly, despite having no visible wings whatsoever. This unfortunate situation, combined with a deeply ingrained unwillingness to question the Dark Lord’s instructions, led to the entire population of velociraptors being launched to their deaths from mountaintops in an attempt to awaken their innate flying ability.
This of course is how the tradition arose of referring to any reptilian steed of the Nazgul as a “Fell Beast.”
It is said that the last words of the ill-fated orc-chieftain in charge of the project were: “As Melkor is my witness, I thought raptors could fly.”