Work after month to find sea creature (7)
I believe the answer is:
Here is my best explanation:
'sea creature' is the definition.
(I've seen this before)
'work after month' is the wordplay.
'work' becomes 'opus' (I've seen this before).
'after' means one lot of letters go next to another.
'month' becomes 'oct' (Oct is an example).
'opus' put after 'oct' is 'OCTOPUS'.
'to find' is the link.
(Other definitions for octopus that I've seen before include "Mollusc with long tentacles", "pernicious organisation", "Far-reaching organisation", "Marine creature", "Spineless creature", "Sea creature's tentacles served as food", "Sea creature - pulpo on a Spanish menu", "large, influential organization", "Tentacled sea creature" and "Sea creature with three hearts".)