'Anqa'a' is Arabic for the phoenix. It's, according to the myth, a bird
that lives for 500 years, after which it burns and dies. Then, a new bird
is born from the ashes. I've read nothing about it being huge.
The Rok, as mentioned in Sinbad's tales, is different. It is just a huge bird.
Funny I never saw the connection before.
Talking about Arabic ancient myth creatures, there's the 'Hamah'. It's
a bird that flies over the murdered man's grave demanding revenge, so to speak, until a revenge is attained.