Run off with social worker, horny creature (8)
I believe the answer is:
antelope
'horny creature' is the definition.
'antelope' can be an answer for 'creature' (type of animal). I also know that 'horny' relates to this answer.
'run off with social worker' is the wordplay.
'run off' becomes 'elope' (synonyms).
'with' means one lot of letters go next to another.
'social worker' becomes 'ant' (ants are social insects).
'elope' after 'ant' is 'ANTELOPE'.
(Other definitions for antelope that I've seen before include "Hoofed beast" , "Reebok perhaps" , "bounder!" , "One leapt badly on the graceful animal" , "A graceful gazelle from Africa" .)