Extreme characters eye Montezuma? (5)
I believe the answer is:
aztec
'montezuma?' is the definition.
(I've seen this in another clue)
'extreme characters eye' is the wordplay.
'extreme characters' becomes 'AZ' (letters at the extremes of the alphabet).
'eye' becomes ''tec' (I've seen this in another clue).
'az'+'tec'='AZTEC'
(Other definitions for aztec that I've seen before include "Montezuma ruled this empire" , "Person of earlier Mexican civilization" , "Ancient Mexican-Indian" , "Such as Moctezuma" , "nickname of US State" .)