Keese

Keese are bat-like creatures that make their homes in dank, shadowy dungeons or in pitch-black caves similar to their real-life counterparts, and have become a staple of the Zelda series, appearing in all mainstream Zelda titles thus far except for The Adventure of Link. The Keese is known to inhabit various forms, some adapted from fire and ice, some from the surrounding environment, however, the technique and strategy used to defeat all of their variations is basically the same.

Characteristics
Keese appear in every dungeon throughout The Legend of Zelda and often exist in clusters about the many rooms in those dungeons, not to mention in the dungeons of the majority of the other Zelda titles, up to Spirit Tracks. These creatures often fly around the screen, not heading towards anything in particular, and stop for a short amount of time on a neighboring wall, or rock face, as seen vividly in The Minish Cap and Phantom Hourglass as well. However, in games such as A Link to the Past and Four Swords, but not exclusively, Keese are easy to startle, and move about the screen only when Link is within close proximity, otherwise they remain still, at rest, on the wall. Unlike the commonplace behavior of the Keese, Four Swords Adventures introduces a variety that can be seen and fought in pure daylight, upon the overworld of Hyrule, as well as in their natural dungeon habitats.

The Keese incarnations seen in The Wind Waker and on through Twilight Princess have a slightly different attack strategy in comparison to the random flight seen in the early titles and the motion sensitivity seen in games such as A Link to the Past and The Minish Cap. Instead of running straight into Link, these bats will hover and pause above him when nearby before hitting him, giving Link a chance to notice and defeat them before they seize the opportunity to cause injury. On another note, the Keese from Twilight Princess, in the same vein with the graphical style of the game, have a much more realistic appearance, and now have a hook-like tail in comparison to the almost non-existent tails of previous incarnations.

Color
The original The Legend of Zelda is the only title to incorporate Keese of any color other than their standard dark appearance. Of the three different colors, Blue Keese are the most common, Red Keese only appear in pairs whenever a Vire, a larger Keese variant, is injured, and the Black Keese seldom appear until the last three dungeons of The Legend of Zelda.

Unusual for the Zelda games (wherein color usually indicates the enemy's level of difficulty), the different colors of Keese have the same abilities, stats, and movement patterns, however, the Black Keese tend to inhabit rooms that are dark or with black floors; in this case, Link could only see their eyes as a method of distinguishment, thus making them harder to locate and defeat.

Size
In certain titles, such as Link's Awakening, Oracle of Ages, and Oracle of Seasons, there are Big Keese that only appear in battle situations. In Link's Awakening, during the fight with the Grim Creeper, the mini-boss of the Eagle's Tower, such Keese attempt to distract Link from defeating the Creeper himself, and in the Oracle titles, these larger varieties are commonly fought in tandem with Blue Stalfos. As would be expected, such versions of Keese are much stronger than their standard forms, but otherwise behave in the same relative manner.

Variations
There are several variations on the regular Keese:

Fire Keese
When Keese are exposed to an open flame, they can transform into Fire Keese. In Ocarina of Time and Majora's Mask, Keese can be transformed by fire arrows or torches (although regular arrows can kill Keese or Fire Keese easily). They will light Link on fire, simultaneously putting themselves out. In Ocarina of Time, if Link has the Deku Shield equipped they could burn his shield. In Twilight Princess, they are almost identical to Keese. The only difference between the two is Link does not take damage if he touches a regular Keese when it's not attacking, whereas he will if he touches Fire Keese. They can be put out with the Gale Boomerang, or any type of Boomerang for that matter, but they do not go out when attacking Link, a trend carried through to Phantom Hourglass and Spirit Tracks.

Ice Keese
Ice Keese are Keese exposed to cold, such as an ice arrow or blue fire (a regular arrow kills them and can kill Keese, as well). In Twilight Princess, Ocarina of Time and Majora's Mask, Ice Keese cannot be changed into regular Keese, nor can regular Keese be transformed into Ice Keese. In Spirit Tracks, they act as a miniboss group before Link obtains the Boomerang.

Shadow Keese
Shadow Keese are only found in the Twilight Realm in Twilight Princess. They have dragon-like bodies and strange, funnel shaped heads surrounded by a ring of gray plumage. Their faces are featureless save for red symbols. They appear to be identical to Shadow Kargaroks except for the fact that they are smaller and weaker. As with many Shadow creatures, Shadow Keese have a distinctive cry; rather than the squeaking of the other Keese variations, Shadow Keese make a noise reminiscent of a hammer clashing on metal.

Vire
Vires are large humanoid bat devils, who fly and hop around the area, sometimes shooting fireballs. They split into two Red Keese when significantly injured. Vire are one of the more intelligent minions in the series, showing the ability to talk.

Similar Species
There are a number of other bat species in the series that are similar to Keese:

Ache
Though Keese don't appear in The Adventure of Link, Aches, a similar species of bat-like creatures, do. Aches in this game are usually found in forests. They hang at the top of the screen, waiting for someone to pass, and dive down to attack them. Blue Aches take only one hit to defeat. It should be noted that the official name of these enemies is actually Ache, but they behave like Keese in almost every respect, so they are often confused with them. In certain towns, some Aches disguise themselves as villagers and attack Link when he tries to talk to them. They are called "The Eyes of Ganon".

Acheman
Red Aches fly down and turn into red devil-like creatures. These Aches, called "Acheman", shoot fireballs from their mouth at their prey. They are only able to transform into this state when on solid ground. They could be seen as the Ache's equivilent of Vire.

Bad Bat
Bad Bats are larger, pure black bats found in Majora's Mask. They seem to prefer outdoor environments, as opposed to the cave or dungeon-dwelling Keese. They are more powerful than Keese as well and appear in huge swarms. A creature called Gomess controls Bad Bats and uses them as a protective cloak.

Chasupa
The Chasupa are Keese-like creatures that dwell in the Dark World and Hyrule Castle Tower in A Link to the Past, although they also share a lot in common with Patra.

Weaknesses
Because Keese are standard and often commonplace enemies, they can be dispelled with any variety of weaponry from swords to boomerangs, arrows to bombs. However, it is advised that even though these bats tend to fly close whenever Link is within range, this is not always the case, so ranged weapons must be used to annihilate these foes at a distance before they interfere with Link's projected path, whatever that may be.

In Twilight Princess, whenever Link uses the Hidden Skill called Shield Attack on a Keese, it will be forced to the ground, hopping and vulnerable to attack.

Trivia

 * In the official Prima Twilight Princess guide, they refer to Keese as "vicious little airborne rodents".
 * In the Kirby series, there is a monster similar to Fire Keese known as Batafire.