Child — crab's claw (6)
I believe the answer is:
nipper
This clue is a double definition.
'child' is the first definition.
(I know that child can be written as nipper)
'crab's claw' is the second definition.
(I've seen this in another clue)
(Other definitions for nipper that I've seen before include "Informal young child or lobster claw" , "Young child or lobster's claw" , "Young person (with claws?)" , "Little chap" , "one given to pinching things" .)