Drunk bringing large snake into bed (9)
I believe the answer is:
bladdered
'drunk' is the definition.
'large snake into bed' is the wordplay.
'large' becomes 'l'.
'snake' becomes 'adder' (adder is a kind of snake**).
'into' indicates putting letters inside.
'l'+'adder'='ladder'
'ladder' placed into 'bed' is 'BLADDERED'.
'bringing' is the link.
(Other definitions for bladdered that I've seen before include "Drunk (slang)" , "Well away" .)