Good news! I got the inside scoop on this ṣafat malarkey. Id save it for the final ABC product, but I need to nip any misunderstandings in the bud before they get out of hand and people start labeling their giant sky cruisers with that name.
First, some breadcrumbing. The ṣafat bird (note the dot under the s – thats a ص) seems to have originally come from (where else?) Roses Giants, Monsters, and Dragons, which in turn got it from Barbers Dictionary, which itself obtained it from Lums Fabulous Beasts. I do not have that last book. Impasse.
I do, however, have access to the most powerful search engines known to humanity, and hey presto – looks like the ur-reference for the ṣafat is Hanauers Tales Told in Palestine.
Going by the title alone, its clear that the ṣafat is not an “Arabian” animal. In the text Azrael – the Angel of Death himself – shows off ṣafat eggshells as something that is a cause of death . He describes the ṣafat as a wonderful bird that never lands (no mention is given as to its size, so I can only assume its normal-sized and not huge). It even lays eggs in flight, and the young hatch before they reach the ground. But then they are often eaten by a shibah (described as resembling a badger-hyena cross. Zorilla? Aardwolf?), which then becomes rabid, goes mad, bites things, and gives Azrael more customers.
There you have it. Far from being a mere permaflier like the allerion or bird of paradise, its literally the cause of rabies.
Clarfication: the eggshells are eaten and cause rabies. The shibah/shibeh is the leopard (!).