Desert beast arrived last - first! (5)
I believe the answer is:
camel
'desert beast' is the definition.
'camel' can be an answer for 'beast' (I have seen 'Beast of burden' mean 'camel' so perhaps 'beast' could also mean 'camel'). I'm unsure of the 'desert' bit.
'arrived last first' is the wordplay.
'arrived' becomes 'came' (coming is a kind of arriving).
'last first' becomes 'l' (1st letter of 'last').
'came'+'l'='CAMEL'
Can you help me to learn more?
(Other definitions for camel that I've seen before include "Humped creature" , "Light yellowish-brown colour - ruminant" , "Cud-chewing mammal of desert regions" , "Pale brown - animal" , "Humped beast" .)