The Goldilocks trio (5)
I believe the answer is:
bears
If this is the answer I cannot explain how the clue works.
Can you help me to learn more?
(Other definitions for bears that I've seen before include "Large animals, polar or grizzly" , "Ursine animals" , "Large animals, polar or brown" , "Carries" , "Massive mammals with shaggy coats" .)