Animals approached outskirts of Leeds (6)
I believe the answer is:
camels
'animals' is the definition.
The answer is an example.
'approached outskirts of leeds' is the wordplay.
'approached' becomes 'came' (come can mean to approach or get closer).
'outskirts of' means to remove the middle letters (only letters on the outskirts).
'leeds' with its middle removed is 'ls'.
'came'+'ls'='CAMELS'
(Other definitions for camels that I've seen before include "Mammals of desert areas" , "Arabs call them ships of the desert" , "Dromedaries" , "Animals known as ships of the desert" , "Old planes" .)