Scamp is unlike the others of his breed (5)
I believe the answer is:
rogue
'scamp' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for rogue that I've seen before include "Bad person" , "Scoundrel, knave" , "one behaving atypically" , "Prankster" , "Profligate" .)