Fabulous creature’s alien character grasped by child (8)
I believe the answer is:
minotaur
'fabulous creature's alien' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'character grasped by child' is the wordplay.
'character' becomes 'tau' (tau is a kind of character).
'grasped by' is an insertion indicator (I've seen this in other clues).
'child' becomes 'minor' (synonyms).
'tau' going into 'minor' is 'MINOTAUR'.
Can you help me to learn more?
(Other definitions for minotaur that I've seen before include "Mythical creature" , "50 per cent ruminant" , "Monster in a maze with the head of a bull and the body of a man" , "Mythical beast of Crete" , "Labyrinth monster killed by Theseus" .)