Mr. X (Tyrant-00)
When you see just how this guy enters Resident Evil 2 I just know your going to be freaked. Then when he attacks it's about as bad. You will be standing there shooting countless rounds in his direction, it might be an easier thing if you just run from him when he attacks you.
Really if you don't have the ammo to take him down (and very early on you probably won't have enough ammo to spare) then you shouldn't bother. However when he does turn up you can get ammo for dropping him so if you think that you do have the ability to drop him do so.
Mr. X (Tyrant 00)'s main role is that of recovery for Umbrella of the G-Virus sample. He won't stop, attacking any he believes have the sample and any who get in the way of him getting it.
Nemesis
Not much is known about the origin of Nemesis. He is much smarter than the average Tyrant, posessing the knowledge to speak the word "Stars" and to wield a rocket launcher. The main guy and subtitle namesake of Resident Evil 3 (although not Biohazard 3-heh). While he might look tough, he's usually easy to avoid, or take down if you take note of how he's attacking. During the game he has three forms. The original is shown to the left, along with two different looks (the 2nd isn't that much of a change from the first as it is more of a lack of his costume that is the main change.)
This is a fight between the two Hand to Hand.
With S.T.A.R.S. members fast becoming a threat to Umbrella's plans, they deploy their latest variation of the Tyrant, the Nemesis to dispose of them. There is also another Tyrant out there Mr. X it was sent to collect the G-Virus sample while looking for it bumps into Nemesis for some reason they(Umbrella) loses control over both of them a all out battle insues WHO WINS????