Journalist hanging around mobile library is a proverbial character (5,4)
I believe the answer is:
early bird
'a proverbial character' is the definition.
The definition suggests a singular noun which matches the answer.
'journalist hanging around mobile library' is the wordplay.
'journalist' becomes 'ed' (short for editor).
'hanging around' means one lot of letters goes inside another.
'mobile' indicates anagramming the letters (mobile can mean moving).
'library' with letters rearranged gives 'arlybir'.
'ed' going around 'arlybir' is 'EARLY BIRD'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for early bird that I've seen before include "communications satellite!" , "first to start in the morning" , "Archaeopteryx, say" , "arriving in good time?" , "one in good time for breakfast" .)