Fairies showing personalities? Not at first (5)
I believe the answer is:
elves
'fairies' is the definition.
(elf is a kind of fairy)
'personalities? not at first' is the wordplay.
'personalities?' becomes 'selves' (I've seen this before).
'not at first' means to remove the first letter.
'selves' with its first letter taken away is 'ELVES'.
'showing' acts as a link.
(Other definitions for elves that I've seen before include "Capricious folk" , "Troublemakers" , "Inhabitants of 8 down" , "Supernatural creatures" , "Santa's little helpers" .)