Here are the enemies that you will encounter in The Legend of Zelda.
 Overworld Enemies
This section will introduce you to many of the enemies that roam the overworld (world outside of the dungeons), and how to defeat them.
Armos seem like normal statues at first glance. They can only be awakened if you decide to touch them so only do so if they are guarding something crucial such as an entrance or item. They are very fast and unless you stun them with a boomerang, they will take off a good amount of your health. When awakening them, don't stand in front of them because you will take damage immediately after doing so.
You will find these guys haunting the graveyard in Hyrule (there is always one of these roaming within a plot cemetery in the overworld). If you touch a gravestone, another Ghini will be summoned and in that screen and you can keep summoning them for however many gravestones you touch. The only way to kill all of them is to kill the original Ghini that was in the screen first (if you've already killed it, you're out of luck). Ghini's are fairly easy to kill.
These sand creatures will attack come up from underground to attack you and then go back down shortly after. Watch for a movement in the ground so that you won't be caught off guard by them. Easily killed once they surface.
A creature that has a horse's body, a lion's head and a man's torso. You can find them in the mountain area of the game towards the final dungeon. These guys wield a shield and sword and the sword can fire beams just like Link's sword when at full health. Lynel's pose somewhat of a threat early in the game since they are in fact the strongest overworld enemy.
Molbin's are Ganon's main source of infantry and they are ugly as heck. They will shoot arrows at you which are similar to a rock projectile but stronger and harder to avoid.
These land octopuses will shoot rocks out of their snouts at you. Use your shield to block the rocks or avoid them altogether. They are very easy to kill even with the Wooden Sword.
These flying flower monsters will fly around for a few seconds and then land. They are invincible while airborne so wait until they land to slash them. Found in packs all over Hyrule, because of the time it takes to kill them, it's best to avoid them.
Four-legged spiders that will jump all over the screen and attack you. The red ones are easier to kill and the blue's are slightly harder. Blue's will leave more Rupees.
Zola's will pop out of a body of water and shoot fireballs at you. They only appear for a second so your only option is to shoot sword beams at them from a distance if you're using the Wooden Sword. If you're lucky, they will appear right next to the shore where you can hit them with the White or Magical Sword for an instant kill. It's best to avoid them though as they are out of reach most of the time.
 Dungeon Enemies
The Legend of Zelda features many exotic and difficult enemies. These are the specific enemies you will encounter within the game's dungeons, and how to defeat them:
Skulls with a white force field surrounding them. They can't be killed, only avoided. If hit by them, you won't take any damage but instead you won't be able to wield your sword for a few seconds. Avoid at all costs!!
Well-armored knights that can only be damaged from behind. These are tricky because they never stop walking and if you try and attack them while they are turned, there is a chance that they can turn around and hit you with their sword. Takes a good amount of hits to defeat them as well.
Attacking a Zol with a weaker sword will turn it into two gels. Incredibly weak, they can easily fall prey to even a boomerang.
Keep your distance when attacking these mummy creatures, they are well-armored and take many hits to kill. When hit, they will not step back like most enemies.
Cloak-wearing rodents who throw boomerangs at you. Fairly easy to kill, they will throw weak versions of the boomerang until you find the Magical Boomberang. Then they too will throw the Magical Boomerag.
Pathetic bats that fly around the room. A well-placed boomerang throw can finish them in one hit.
A centipede that will scuttle across the dungeon floor. It has body segments so just continue slashing until only the head is left and kill that. They will move in random directions.
 Like Like
These slow-moving blobs are the most irritating enemies in the game. They will slowly make their way across the room until close enough to eat you up. If eaten, you will be held there and more often than not your Magic Shield will be eaten and you'll have to get a new one. Stun the Like Like with your boomerang and clear the screen of all other enemies before finishing it off. Easy to kill.
These red worms are slow versions of the Lanmola that will crawl around in the sand. They too have body segments and you'll have to work your way down to the head for the final blow.
Patra's are giant eyeball creatures with smaller versions serving as a forcefield. Sometimes the smaller ones will form a larger circle so keep your distance when necessary. Once the smaller ones have been killed, the large Patra is vulnerable and easy to kill. Only found in Ganon's Lair.
 Pols Voice
These odd creatures with rabbit ears take many hits to kill and they move in a vertical line. Arrows can kill them instantly so make sure you have them with you in this case.
Snakes that are very easy to kill. If you cross their line of sight which is directly beside or in front of them, they will attack.
Skeleton warriors who wield swords. They pose no threat at all and are extremely weak.
Easily slain blue demons. Attacking with a weak sword will cause the Vire to split into two red Keese which are the same as black ones.
These hand demons will slowly come out of walls and try to grab you. If caught, you will be brought back to the beginning of the dungeon. Attack them from a distance so as not to get caught by another enemy. Usually found gaurding the room before the boss.
These magicians will cast spells of energy at you which can do a substancial amount of damage. They will float around the room and attack you from a distance. Red ones are easier to kill where Blue's are more hostile and do more damage.
These blobs are extremely slow and will move around the room randomly. Slash one with a weaker sword to cut it into two blobs or use a stronger sword to one hit kill.