University lecturer holding newspaper showing monster (6)
I believe the answer is:
dragon
'monster' is the definition.
(I know that dragon is a type of mythical creature)
'university lecturer holding newspaper' is the wordplay.
'university lecturer' becomes 'don' (don can mean an academic - especially at Oxbridge).
'holding' is an insertion indicator.
'newspaper' becomes 'rag' (informal term for a newspaper).
'don' enclosing 'rag' is 'DRAGON'.
'showing' acts as a link.
(Other definitions for dragon that I've seen before include "Fiery monster" , "eg Puff, Fafner" , "Mythical fire-breather" , "Formidable woman" , "[TERMAGANT]" .)