The most common and most likely answer to this crossword clue is the 3 letter word ROC
I've seen this crossword clue in The Times
R
O
C
More clues leading to the result ROC
- Legendary bird biting head off dangerous reptile
- Legendary winger caught by old right back
- Fabulous bird eaten by crocodile
- Give a lift to my fabulous bird
- Finally refer to exotic mythical bird
- Fabulous bird to rise quickly? Not half
- Fabled bird seen in stone, it’s said
- Fabulous great bird biting head off reptile
- Fabulous bird having origins in Russia or China
- Fabulous flyer missing end of crag
Buddy explains!

The straight part
We know that "Fabulous bird" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fabulous bird = roc.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ROC mean?
ROC noun- An enormous mythical bird in Eastern legend.
- Rocuronium.