The Killtastrophe medal is represented by a light blue circle with eight silver stars. This medal is extremely hard to get because of the combined difficulty of killing eight people in a row without getting killed within a certain time limit. One method of earning the medal is to wait at a common place or doorway and when enemies come down or come around the corner you kill them (Note: This only works if there are a large number of players). Another option is throwing a Trip Mine into a group of enemies.
To further this effect, throw a grenade with the Trip Mine. This will cause more damage and finish off people who have their shields down from the Trip Mine. There are only two medals above this prestigious medal, which are the Killpocalypse and Killionaire medals.