i think he meant to send a packet that simulates a "being-killed-mob"
but as already mentioned its nearly impossible to do so,
because:
1) the mob would be a non existant one you created
2) its not only 1 packet, but alot more
3) and the other packets would cause errors
/!\ that would need new packets to fix /!\
simply the whole question/answer interaction with the server wont work...
hopefully you understand that your idea is too far fetched
and it will save you some time