The Dark Assassin is an enemy found in Chaos 5+ that specifically targets players. Teleporting to it's victim, it grabs on, stabbing them multiple times. Players are unable to attack while grabbed, but can still move around. This last for about 5 seconds before the Assassin will let go and attack another victim.
Whispers can be heard if they are nearby. Indicators that Assassins are about to attack are the purple glowing swirl surrounding the neck and head of its victim, coupled with a unique targeting sound effect.
The mini-boss variant for Dark Assassin is Skarnash the Terrible, a red Dark Assassin. Just like regular Dark Assassins, Skarnash teleports to players from spawn. It is immune to being knocked up, but can still be stunned.
A good strategy for dealing with Assassins is standing in auras or in front of heavy hitting towers so that for the duration you are unable to attack, your towers/auras can. Towers with the ability to stun or knock enemies up, such as the Viper's Fangs or Geyser Trap, can remove the Assassin. Pet abilities can be utilized, even while under attack, so it is a good idea to activate it to kill the Assassin. You are not safe from the dark assassin if useing the lavamancer Submerge/Emerge
A common issue players will have with Assassins is their splash damage when they first grab a victim. This splash can damage, or destroy, a core if the hero picked by the Assassin is near one at the time of their attack. It is a good idea to stay away from the main objectives in Chaos V and above.