Surrealist dunking fish factory in gin, as weird (5,8)
I believe the answer is:
spike milligan
'surrealist' is the definition.
(surreal comedian)
'dunking fish factory in gin as weird' is the wordplay.
'dunking fish' becomes 'pike' (I can't justify this - if you can you should believe this answer much more).
'factory' becomes 'mill' (synonyms).
'in' is an insertion indicator.
'weird' is an anagram indicator.
'pike'+'mill'='pikemill'
'gin'+'as'='ginas'
'ginas' anagrammed gives 'sigan'.
'pikemill' inserted inside 'sigan' is 'SPIKE MILLIGAN'.
(Other definitions for spike milligan that I've seen before include "Author of Silly Verse for Kids" , "zany personality" , "Comedian - alien milks pig (anag)" , "Comedian and author" , "Goon who wrote "Silly Verse For Kids"" .)