Dead by Daylight

As the killer you need to unlock the Memento Mori offering and then use it in a match. After the match you will lose the offering. What it does is it will allow you to kill players crawling on the ground without having to pick them up and bring them to hooks.

Here are the three Mori offering types:
Cypress Memento Mori - Yellow offering where only the final survivor in the match can be killed
Ivory Memento Mori - Green offering where any one survivor can be killed, the first/second/third/last doesn't matter
Ebony Memento Mori - Pink offering you can kill any and all survivors

You just need to kill one survivor this way for this specific achievement but you'll want to get as many as you cna as two more achievements are related to getting kills this way.

The Pig killer apart of the Jigsaw DLC has a reverse bear trap they can place on survivors knocked to the ground.
This is highly situational as they'll need to be then put in to a walking around state and only after a generator is activated will the traps start a countdown timer. Once the timer ends you'll get the kill. The problem is that these boxes with the Jigsaw puppet on top of them can be used by the people with the reverse traps for a chance to take off the trap.
I believe you only get four traps and you can not replenish them so if the survivor take off all your traps then you won't be able to get any progress via this method.
I think if a survivor tries to escape via an exit gate then trap will automatically go off before they can. Not sure about hatches.
Credit to Scipio527 for pointing this out.

Can also be done with The Shape (Michael Myers) killer from The Halloween DLC if you have his ultra-rare add-on which you can read more about here:

Credit for pointing this out goes to Mishqqa.

Shield Papa also wrote a Mori guide that involves the Hag:
Solution for Blood on your hands In Dead by Daylight

To get his achievement you can, like the solution above, get any of the Momento Mori offerings, which will show up in the blood web of every killer.

Or... you can unlock The Hag's teachable perk " Hex: Devour Hope". This perk is tied to a hex totem, which means that survivors can get rid of it though the match. But it will allow you to kill survivors after you hook them and allow them to be saved by other survivors 5 times.

This killer perk can allow you to also get "Blood on your face" without needing the Ultra Rare Ebony Momento Mori

If you play as The Pig, put a reverse bear trap on someone's head, and it ends up killing them in the 2 minutes it takes, you will get the achievement for killing them.