Animal always close to desk occupying rug (7)
I believe the answer is:
meerkat
'animal' is the definition.
(I've seen this before)
'always close to desk occupying rug' is the wordplay.
'always' becomes 'eer' (poetic way of saying ever).
'close to' suggests the final letters (the close/ending of).
'occupying' means one lot of letters goes inside another.
'rug' becomes 'mat' (I've seen this before).
The final letter of 'desk' is 'k'.
'eer'+'k'='eerk'
'eerk' placed within 'mat' is 'MEERKAT'.
(Other definitions for meerkat that I've seen before include "Tee mark, oddly, on the four-toed catlike animal" , "Small South American cat-like animal, has four toes" , "S African mongoose-like creature" , "Small mongoose of southern Africa" , "Mongoose-like mammal of southern Africa" .)