The zombie is the most common enemy in the game, the poor residents of Raccoon City who became infected with the T-Virus.
There are many different types of zombie in the game, from normal men and women, police officers, scientists, and test subjects.
The zombie is an easy enemy, as long as they're in small numbers. The Handgun is enough to keep them at bay. It's possible to decapitate one or many zombies with a single shotgun blast, simply aim up when they come into grabbing range, and fire.
The zombie dog, unlike the Cerberus, was not an experiment, but more of an accident. When exposed to the T-Virus, the creature mutates. However, the movements and attacks are practically identical to that of the Cerberus.
The easiest way to deal with these dogs is by using the handgun. Wait until they come at you, and fire a single shot. Wait until they stagger to their feet and prepare to pounce, then fire again. Keep repeating until they're dead. The problems come when you're surrounded, as their jumping bite attacks could be fatal if delivered one after the other constantly.
Larger and more aggressive than normal, these birds will sit patiently unless they consider you a threat. It seems these crows feasted on a corpse infected with the virus, and driven them to act like something out of an Alfred Hitchcock novel.
You won't encounter crows very often during the game. Its better just to avoid them, however if you do want to take them down, don't use anything larger than the Handgun.
These are ordinary cockroaches that have become exposed to the T-Virus, making them far more aggressive. Despite only encountering them a couple of times during the game they should be feared. If you find yourself surrounded by these pests do your very best to escape to the nearest door or ladder, as they hit you with tiny little bites over and over again which will drop your health at an incredible rate.
A normal alligator that has grown to enormous size, big enough to swallow you whole. Most likely a pet of a resident of Raccoon City, who flushed it down the toilet. Now in the virus infected passages of the Sewers, it got infected, and emerged as this monster.
There are two ways of killing this creature, either go in with guns blazing, filling it full of everything you've got, until you're backed up against the wall. Eventually you will scare it away, until Scenario B where you have to fight it again. Using the same tactic in the second scenario will kill it. Alternatively, about halfway along the corridor there's a switch on the wall to release a high-pressure gas canister. If you release it when the alligator is chasing you, it will eventually end up in its mouth. Fire a shot from any weapon to blow its head clean off.
This mysterious man will follow you around the R.P.D. Building in the second scenario. His intentions are unclear, but he doesnt hold back when you encounter him.
With enough bullets you can bring him down, but it's just better to avoid him. He only has two main attacks, either a swing with his fist, or a full-on slam with his arms. When he come to take a swing at you, step back so he misses, then quickly run past him. The reward for bringing him down is a small amount of ammo, the type and quantity depend on whereabouts you encounter him.
After the Tyrant falls into the molten steel vat, the damage he receives is extreme. With its limiter destroyed, there's nothing stopping this Tyrant from undergoing a mutation to reveal its true self.
This time the Tyrant won't hold back, he will charge at you every chance he gets. The same tactics apply for the Tyrant at the end of the first game, just avoid him for a few minutes until a mysterious woman drops you a Rocket Launcher. Use this to finish it off once and for all.