Like the mythical orc, maybe, it never really existed (3)
I believe the answer is:
roc
'it never really existed' is the definition.
The definition suggests a singular noun which matches the answer.
'like the mythical orc' is the wordplay.
'orc' can be anagrammed to 'ROC'.
But, I am not sure how the anagram is indicated.
'maybe' is the link.
Can you help me to learn more?
(Other definitions for roc that I've seen before include "Sinbad's giant bird" , "Enormous legendary bird" , "Enormous, mythical bird of prey" , "Mythical bird; sounds like boulder" , "Mythical creature from Arabia" .)