Mess maker (4)
I believe the answer is:
'mess maker' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for slob that I've seen before include "Slovenly person (colloq.)" , "Boor" , "Fat, idle type" , "Fat, idle person" , "Slovenly and unkempt type" .)