The affix ṭak comes after the verb han 'to kill' when the object is in composition with it and when the word to be formed denotes an agent other than a human being.,
As जायाघ्नस्तिलकालकः 'the mole' (literally that which indicates the death of one's wife); पतिघ्नी पाणिरेखा 'the line of the palm of the hand' (that which indicates the death of one's husband). These two forms were deducible also from the last aphorism. श्लेष्मघ्नं मधु 'honey' (literally that which has the property of destroying the phlegm). पित्तघ्नं घृतं 'clarified butter' (lit. that which destroys the bile).
Why do we say 'when the agent is not a human being'? Observe आखुघातः शूद्रः 'a Sudra' (literally one who kills the mice). Here the affix is अण्.
Why is the affix टक् not employed in the following? चौरघातो हस्ती 'an elephant' (i.e. who kills a thief.) Here the word is formed by the affix अण् on the analogy of sutra 3.3.113 which allows a diversity in case of kritya affixes, which diversity is extended in this case to a krit affix.,