He's in jug (4)
I believe the answer is:
toby
This clue is a double definition.
'he's' is the first definition.
'jug' is the second definition.
(I've seen this before)
'in' is the link.
(Other definitions for toby that I've seen before include "fellow" , "dog with frill round neck" , "Kind of jug" , "This Jug is like man with three-cornered hat" , "Belch, perhaps" .)