The French doctors are frolicsome creatures (5)
I believe the answer is:
lambs
'frolicsome creatures' is the definition.
'lambs' can be an answer for 'creatures' (lamb is a kind of creature). I'm unsure of the 'frolicsome' bit.
'the french doctors' is the wordplay.
'the french' becomes 'la' ('the' in French).
'doctors' becomes 'MBs' (Bachelors of Medicine).
'la'+'mbs'='LAMBS'
'are' acts as a link.
Can you help me to learn more?
(Other definitions for lambs that I've seen before include "See 17" , "Young sheep" .)