Big and strong, he gets a bit crafty (5)
I believe the answer is:
hefty
'big and strong' is the definition.
(I've seen this before)
'he gets a bit crafty' is the wordplay.
I cannot really see how this works, but
'he' could be 'ty' and 'ty' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for hefty that I've seen before include "Sizeable" , "Burly" , "With weight" , "Large, heavy" , "Hulking" .)