The beast arrived and left (5)
I believe the answer is:
camel
'the beast' is the definition.
(type of animal)
'arrived and left' is the wordplay.
'arrived' becomes 'came' (come can mean to appear or arrive).
'and' is a charade indicator (letters next to each other).
'left' becomes 'l' (common abbreviation).
'came'+'l'='CAMEL'
(Other definitions for camel that I've seen before include "Saharan carrier" , "Desert ruminant" , "African transport" , "African carrier" , "Light yellowish-brown colour - ruminant" .)