Praying preyer (6)
I believe the answer is:
mantis
'praying preyer' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mantis that I've seen before include "Insect in attitude of prayer" , "A praying . . . . . . is a kind of grasshopper" , "Actually it preys rather than prays" , "may be praying" , "Large insect (sometimes praying?)" .)