Excessively large puppet (4)
I believe the answer is:
tool
'puppet' is the definition.
('tool' can be a synonym of 'puppet')
'excessively large' is the wordplay.
'excessively' becomes 'too' ('too' can be a synonym of 'excessively').
'large' becomes 'l'.
'too'+'l'='TOOL'
(Other definitions for tool that I've seen before include "Utensil; implement" , "Device used for work" , "Weapon" , "Person exploited" , "Drive motor skilfully" .)