Elementals are the most unadulterated form of the elements of which they are composed. Hailing from the elemental planes or the elemental chaos, these sentient creatures are essences of fire, air, water, and earth that take on a life of their own. Rather than being born through reproduction like most other species, elementals are birthed as a result of devastating force unleashed by natural disasters.
The latent energy inside of tornadoes, typhoons, volcanic eruptions, and earthquakes sometimes coalesces into these living forms. Since the Dungeons and Dragons world was originally created out of the destruction these forces wrought, elementals are perhaps the most ancient beings to walk the planet. In their timeless age, many of these creatures have fostered devastating power.
10 Elemental Myrmidon (Water, Fire, Air, Earth)
Elemental myrmidons are fashioned through a little known ritual that involves specific sets of plate armor. These sets of armor are used to magically bind elementals inside of them, wiping the elemental's memory in the process. With no recollection of their past lives, myrmidons make perfect servants for those with the magical know-how to force them into such armors.
9 Frost Salamander
Frost salamanders are quite similar looking to the monstrous behirs and sport a breath attack just like their lightning lizard lookalikes. Furthermore, frost giants occasionally capture and tame frost salamanders in order to take advantage of their useful capability to burrow through ice. In short, frost salamanders and behirs have a lot in common. These ice newts hail from the elemental plane of ice, sometimes called the Frostfell. As is the case with all elementals, sometimes these creatures do escape to the material plane where their affinity for hunting warm-blooded creatures quickly draws attention to their presence.
8 Dao
Dao are one of four types of genie that are created in each elemental plane. A genie comes to life when the soul of a once living creature melds with material from the elemental planes. The genie has no memory of its soul's previous life. While genies are identifiable by most for their ability to grant up to three wishes, only a select few genies actually possess this power.
The Dao hail from the elemental plane of earth, where they have created an empire of their own primarily through the use of slave labor. Unlike other creatures that burrow through the earth, the Dao can move through rock as if under the effects of the meld into stone spell. As a result, they leave no trace when moving through earth and can travel through it as easily as though they were flying through the sky.
7 Djinni
Djinni were birthed from the elemental plane of air and their personalities match the tumultous nature of their home plane. As punishment for aiding the elementals in their war against the gods ages ago, most djinni were imprisoned in common household objects such as the ever-popular lamp. While they have no need for food, drink, or other such material pleasures, djinni, nonetheless, greatly enjoy the finest of delights that the material plane has to offer.
6 Efreeti
The efreeti are lesser genies birthed from the elemental plane of fire. Like the fires from which they are formed, efreeti are given to passionate emotions such as anger and revenge. While water gives life to most other life forms, the efreet are nourished by fire instead. Consequently, efreeti who escape the elemental plane of fire make their homes in scalding hot environments such as deserts and volcanoes.
The efreeti are known among their genie brethren for their cruel nature. They see themselves as superior to most other life forms, and this superiority shows in their cruel behavior towards non-efreet. The efreeti are renowned for their skill in the forge, particularly in forging magic armor and weapons of a more fiery persuasion.
5 Marid
The marid are elemental genies from the elemental plane of water. Like their Dao brothers, marid also possess the power to grant wishes. However, marid purposefully twist the wishes they receive into undesirable outcomes. For example, a creature that wished for the power of flight from a marid might be turned into a bird. Marid can easily be considered the least trustworthy of all genies one might encounter. Like their efreeti brothers, the marid consider themselves the most wondrous of all genie kind. The only difference is that they are probably right. Marids love to tell stories, especially those that paint themselves and other marid as legendary. Interrupting a marid's tale is perhaps the most surefire way to get on its bad side.
4 Phoenix
The phoenix is one of two forms that elder elementals take. An elder elemental is created when a lesser elemental feeds on the essence of enough of its kin to transform into a tempest of elemental energy. These beings are apocalyptic by their very nature. Summoning one to the material plane is a promise of destruction to come. When a phoenix enters the material plane, the sky is bathed in an explosion of fire. The phoenix is driven by one goal: burn everything to ash. While a phoenix might be beaten into cinders, it can never truly be defeated. Its ashes are impervious to all damage and will burst into a newly formed phoenix within 1d6 days of death.
3 Leviathan
Leviathans are the elder elemental form that water aligned elementals take. Made of many walls of water, the leviathan takes on a serpent-like form as it pulls galleons to the depths of the oceans and sweeps coastal settlements underwater. While considerably more powerful than its phoenix counterpart, leviathans are thankfully held at bay by the land. These gargantuan monsters can usher tidal waves from huge bodies of water, drowning entire civilizations in their mission to submerge the world.
2 Zaratan
The Zaratan is the elder form of earth elementals. These beings manifest as giant tortoises composed of earth. As a zaratan walks across the land, earthquakes usher in its footsteps, and avalanches answer its gargantuan form. Zaratans bear their own self-defense mechanism, using their turtle-like form to shield itself when its presence on the material plane is threatened.
The zaratan can revitalize itself during this retraction by melding the earth beneath it into its form. While even more powerful than leviathans, zaratan do have a glaring vulnerability to thunder damage.
1 Elder Tempest
Elder Tempests are the most powerful of elder elementals. Formed by air elementals that feast on enough elemental essence, elder tempests are a blur of dark clouds, thunder, lightning, wind, and rain in the shape of a many winged sky serpent. Terrifying storms at least 5 miles in diameter follow them wherever they go, imposing disadvantage on all ranged attack rolls. Seeing as elder tempests normally remain high in the sky, it's no surprise that this might pose a problem. While elder elementals are truly apocalyptic forces of nature, they don't often visit the material plane. The only way for elder elementals to leave their home planes is through ancient rites buried by time in the greater interest of the world's survival. Even so, the most devoted cultists of elemental evil are sure to seek such measures out.