The animal arrived at Leatherhead (5)
I believe the answer is:
camel
'the animal' is the definition.
(I've seen this before)
'arrived at leatherhead' is the wordplay.
'arrived' becomes 'came' (come can mean to appear or arrive).
'at' is a charade indicator (letters next to each other).
'leatherhead' becomes 'l' (head letter of 'leather').
'came'+'l'='CAMEL'
(Other definitions for camel that I've seen before include "Saddle animal in desert regions" , "Cud-chewing mammal of desert regions" , "Humped creature" , "Saharan carrier" , "quadruped" .)