Tartarus is the first boss any player will face in Night of the Dead. He is a large bulbous creature hatched from an enormous egg found in the Airlock doors. His stubby legs and flabby exterior hide the fact it is faster and more heavily armored then he first appears.
The key to defeating Tartarus is to always have as many players firing at his backside as possible. The best strategy is to decide as a group which players go where. Tanks should go to one direction, while the rest of the team goes the other. The tanks should try to constantly keep Tart agro'd, while kiting to avoid as many hits as possible. Reactive Armor or the clever use of Nano-Shield can allow for relatively safe facetanking. Depending on difficulty, when Tartarus's frontal armor increases, he can potentially become near invulnerable to frontal attacks. Spinning or drawing the beast away is especially useful during this period. Stuns are incredibly helpful when dealing with Tartarus, as they can hold him in place allowing free damage output on his rear. Sonic Traps or Disruptor Towers are good for keeping his banelings and blindings at bay.
Unlike any other boss, it is possible for Tartarus to be captured alive for bonus experience. To do so, injure him until General Koller radios that he wants your team to capture the creature alive to be studied. At this point, you need to hit Tartarus in the rear with a High Damage Skill while he is stunned. Any stun will do, but thus far only Monofiliment Cartridge, One Shot One Kill, Nano-Shock and Precision Shot have been confirmed to work.
When Tartarus becomes sufficiently injured, his frontal armor and health regeneration become significantly better. How soon this occurs and how effective the ability is is mostly dependent on difficulty. The armor will decrease skill damage as well, so characters with damaging skills should try to reposition to the sides or rear for maximum effect. Tartarus turns yellow when his carapace hardens.
As the battle drags on Tartarus will become faster and faster. It is best to kill him as quickly as possible, as his speed reaches certain thresholds he becomes almost impossible to effectively kite or even run away from. This ability is largely to prevent any kind of exploit or cheese strategy against the boss. The movespeed caps out at 2.8.
Throughout the battle, Tartarus will spawn Blindling, Baneling, or Beastling depending on the campaign difficulty. These are generally hard to avoid. Either try to kite and target them manually, or make sure that getting hit won't seriously endanger your life. As the fight wears on, the number of Banelings Tart can summon will increase.
Tartarus is able to climb up cliffs. This is typically a non-issue when fighting Tartarus, but any attempt to use high ground against Tartarus is fruitless.
When Tartarus dies, all the banelings, parasites, and other creatures stored inside him erupt out in a final wave. They are generally considered "free" experience, but the combination of blindness and venom stack can be fatal. Best for all players to keep their distance when Tart is close to death. When he does die, deploy a sonic trap to push back the mob, have disruptor towers up to soak up kills, or use Escape to cloak the team. The combined experience from this mob can easily level up several players if handled properly.