Mafia III

This can be done at any point during your playthrough, but the first and easiest opportunity is during the prologue mission.

Once you have control over Lincoln, head into the storage room inside the garage and pick up the body on the floor. Now leave the garage and walk towards the edge of the dock outside. You can throw the body over the railing into the water; one of the alligators will eventually eat the corpse, thus unlocking "Bon Appétit."

Then, in order to unlock "Next Time Swim Faster," simply jump over the railing and into the water yourself. Wait until one of the two alligator attacks. The achievement will unlock once you have been eaten.