Zombies Found throughout the entire game; you deal with several different types. Not really harmful since they are slow and cause minor damage. If you want to save ammo simply avoid them by running past them.

MA-39 Cerberus Found throughout the entire game as well; they stand next to the level of zombies. I feel these creatures are as well minor to worry about. You can avoid these creatures as well by simply running from them. Otherwise take the Beretta out and kill them.

Yawn Found in the attic and 2nd floor (Ball Room) of the Mansion. Four shots from the Bazooka will put this creature into it's misery. You could try and avoid it, but that would ruin all the fun!

Snake(s) Drop from the trees outside the shed on your way to the Guard (Residence) House or sewers. Just like the Bees they are poisonous so just try to avoid them.

Fi-3 Neptune Found in the basement of the Guard (Residence) House (2 small & 1 large); the tank they were once in broke and they now swim about themselves throughout that area.

Plant 42 Found in the Guard (Residence) House. Depending on how you play the game, either you will have to kill the Plant yourself or someone will save you. I won't spoil it if you haven't played it. Kill the roots in the basement to make it weaker (Hint: V-Jolt!). Tip to beginners, don't just stand around, make sure you move and shoot, otherwise you will get attacked.

Mutated Spider(s) Found in Mansion and Guard (Residence) House. After you kill one of the big Spider(s) , little Spiders come out and start jumping around and biting you so word to the wise there.

Bee(s) Found in Guard (Residence) House. You only have to deal with these creatures (if they even are, maybe just normal?) once (after you take the 'Room 003' key). If you do get attacked you can get poisoned.

MA-121 Hunter Once re-entering the Mansion after destroying Plant 42 you will be treated with a FMV clip and you will meet your first Hunter. They are all over the mansion and in the sewers. Keep your distance and definitely don't stand around. One swipe and they can take your head off. Shotgun and Magnum are useful weapons with these creatures.

Lab Monsters (Chimera) Found in the labs 'Power Room' and then after you defeat the Tyrant in the lab. They dash towards you, hang from the ceiling and claw the hell out of you if you get cornered. You can avoid them by running but I'd prefer to shoot them dead.

T-002 Tyrant As many know there are several different endings. So you may face him only once or maybe if your good enough, you'll face him more then once. In the lab simply run around the room with Tyrant following you. With distance fire, and continue in this manner. Like I said, if your good enough you will meet again.