Lizalfos

Lizalfos are lizard-like creatures that are found in several Zelda games.

Characteristics
Lizalfos wield quite strong swords. It is usual that they confront Link in pairs, but he will only have to actually fight with them one at a time. When one gets injured, it steps back and the less-injured one takes charge. They are very agile in combat and tend to swing for Link at a certain time, but there are always small opportunities to attack when they drop their guard. They tend to circle Link first and then approach on the counter attack.

The Adventure of Link
While Lizalfos do not appear in games prior to Ocarina of Time, similar enemies known as Geru appear in The Adventure of Link. These enemies may of provided inspiration for Lizalfos.

Ocarina of Time
Unlike Geru, Lizalfos only appear with swords as weapons. They also have much less armor but are much more agile, as they are able to jump far away from Link's attack range. First appearing in the Dodongo's Cavern in pairs as a mini-boss, the attack one by one, switching to the next in a tag-team style after one sustains enough damage, while the other stays far out of Link's range. Lizalfos are scarce within this game, only appearing as regular enemies later in the Spirit Temple and in certain other dungeons in the Master Quest. A similar enemy, Dinolfos, appears later in this game, as well as in Majora's Mask.

Twilight Princess
In Twilight Princess, Lizalfos have a more dinosaur-like appearance and have ax blades roped to their tails as a secondary weapon. They come in two varieties, the normal "Axe-Tail" variety and the "Skull-Face" variation, wearing skull armor for extra defense. They fairly easy to kill with Bomb Arrows or swordplay such as the Back Slice, and Wolf Link is able to leap and bite at their throats. A single Mortal Draw is also able to quickly dispose Lizalfos. Lizalfos are much more common than in Ocarina of Time and often appear in parts of Hyrule Field, as well as numerous dungeons, including the Lakebed Temple, Temple of Time, the City in the Sky, Hyrule Castle and the Cave of Ordeals.

Much like in Ocarina of Time similar but much larger and heavily armored enemies known as Dinolfos (also known as Dynalfos in this game) first appear in the Temple of Time. They are considerably more dangerous opponents capable of frequently dodging the Ending Blow and blocking other hidden skills and attacks.

The mini-boss Darkhammer is possibly a large Lizalfos covered with armor found in the Snowpeak Ruins. It wields the Ball and Chain, a weapon Link needs to progress through the game. Darkhammer wears very heavy armor covering its entire body save for its tail, which is its only vulnerable point. It attacks by swinging the Ball and Chain wildly in circles, knocking Link backwards if he is hit. However, its main attack flaw is that as long as it was swinging its weapon it had little in the way of a close range attack.

Skyward Sword
In Skyward Sword, Lizalfos first appear as regular enemies and a pair as mini-bosses in the Earth Temple guarding the Bomb Bag, similar to their first appearance in Ocarina of Time. They later appear as enemies at Eldin Volcano Summit. Like many of the enemies in Skyward Sword, this is one of their stronger appearances. Lizalfos in Skyward Sword have one large, rocky guantlet that they can defend and attack with. They also have morningstars on their tails, similar to the axes on Twilight Princess incarnations, and are able to breath fire like Dinolfos from Majora's Mask.

Dark Lizalfos are dark blue/black Lizalfos that appear as mini-bosses in the Fire Sanctuary and as well as being stronger then the normal variety they are able to curse Link with their dark fire breath. They also appear to have large bright orange crests that sit upon the top of their head. They appear in the Fire Sanctuary and the Sky Keep.

Defeating either of the two varieties of Lizalfos will make it drop its tail, which can be collected as treasure.

Trivia

 * Interestingly, in Twilight Princess, arrows will stick to Lizalfos indefinitely and can be retrieved.
 * Dark Lizalfos have crests on their heads similar to Daira from The Adventure of Link.