Monster note in Scandinavian currency (4)
I believe the answer is:
ogre
'monster' is the definition.
(fairy tale monster)
'note in scandinavian currency' is the wordplay.
'note' becomes 'g' (musical note).
'in' is an insertion indicator.
'scandinavian currency' becomes 'ore' (I've seen this in another clue).
'g' put within 'ore' is 'OGRE'.
(Other definitions for ogre that I've seen before include "One making giant strides" , "Fairy tale monster" , "Evil giant" , "Cruel, fearsome person" , "Giant of folklore who liked to eat humans" .)