Castlevania II: Simon's Quest/Enemies

Mansion only enemies
In addition to Slimes and Spiders described above, you will also encounter these enemies inside the mansions.

Death
Death is most likely the first boss that you will encounter. He awaits you in a chamber before the Dracula part in the third mansion. He hovers in the air and has two main attacks: throwing small sickles at you and slashing you with his scythe. He slowly floats towards you and starts slashing. The sickles will begin to appear as soon as you enter the room.
 * AKA: Grim Reaper
 * Location: Braham Mansion
 * Reward: Gold Dagger

To defeat him, approach him and whip him as fast as possible. When he gets too close, run under him to an new spot and repeat until he dies. If you wish to slow him down, you can mix in some attacks with the Mystic Flame once he is close enough to the ground for the pillars to reach him. The flame will lock him in place while you attack him.

Fighting Death is actually optional, though you shouldn't ignore him if you wish to obtain the powerful Gold Dagger. If you don't want to fight him, you can choose to ignore him and go through the door on the right to reach the orb. Regardless of whether you defeat him or not, Death will always return when you enter the room.

Carmilla
Though one of the most iconic bosses of the Castlevania series, Carmilla is not tremendously difficult to defeat, especially if you have Dracula's Rib equipped as a shield when you fight her. Carmilla, or more specifically her mask, hovers in midair, out of reach. Her primary attack is to drop bloody tears, which explode into a multi-directional burst when they hit the ground. However, the Rib will absorb these particles and prevent you from taking damage (provided you don't try to walk at the same time). Her other attack is to swoop around the room in a loop (she often does this several times in a row). Stand back just far enough to remain out of reach when she moves, and jump and hit her with your whip. Although she can do little to harm you, she has quite a lot of health, so you will have to hit her many times before she is defeated.
 * AKA: Crying Mask, Bloody Tears, Vampira
 * Location: Laruba Mansion
 * Reward: Magic Cross

Just as with Death, you can ignore Carmilla and simply go into the orb room. However, you will be unable to complete the game unless you kill her at least once. The Magic Cross is needed to get into Dracula's Castle and it can only be retrieved from her.

Unaware of the significance of the Carmilla character to the Castlevania series, this boss was originally labeled the Weeping Mask or Crying Mask in the North American release. She is the same Carmilla who would reappear in Dracula X: Rondo of Blood and Castlevania: Circle of the Moon (which mistranslated her name as Camilla).

Dracula
The source of Simon's problems, and the last boss of the game. By taking the five parts to his castle, Simon revives the Count so that he can finish him off and break the curse. There are multiple strategies to use against Dracula, some easier than others.
 * Location: Dracula's Castle

For a simple method, start throwing Sacred Flames at Dracula's feet as soon as you regain control. Keep throwing them, one after another, and Dracula won't even be able to move.

For a greater challenge, wait for him to begin his attack. He'll start orbiting the room so rapidly that multiple images of him will appear, while throwing large spinning fireballs at you. The best place to be is in the center, on the altar where Dracula initially appears. Use your whip continuously, and you should be able to hit the Count, as well as destroy his fireballs. The Diamond or Gold Knife can help a bit, as they are both capable of hitting Dracula several times.

Whichever method you choose, once you defeat Dracula you'll see one of three endings, depending on how long it took you to complete the game.