You have learned to put the Embalmed Cadavers in their place—6 feet under the ground.
How to Get
Hero side, the easiest way to get this badge is to hunt the Embalmed Cadavers and Embalmed Abominations in the either the Bettis Hills area of Perez Park or in the Sewers. It is advisable to do this at a higher level, where it's possible to just run from group to group of Vahziloks', killing Embalmed Cadavers and Embalmed Abominations and ignoring the others.
Another good way to at least get a good start on the badge is participating in the Positron Task Force which has several missions filled with Vahzilok and if the team size is 7 or 8 you will find a good many of the Emablmed Cadavers that way. At the same time you fulfill on of the requirements needed for the Task Force Commander Badge accolade.