Fatla

Fatla (ファートラ) is Beelzebub's secretary. Fatla is a side character of the Slime Taoshite 300-nen, Shiranai Uchi ni Level Max ni Nattemashita series. She is a Leviathan demon and the air-headed, competent older twin sister of Vania, and serves as Beelzebub's assistant in the Ministry of Agriculture in the Demon Kingdom.

Background
Before the main story events, Fatla and Vania were employed as secretaries in Beelzebub, but there is limited knowledge about their previous roles.

In Chapter 18, A Leviathan Dropped By, Vania made her debut appearance with her sister, Van. They arrived to escort Azusa and her companions to the Demon Realm. Vania served as the guests' attendant while Van transformed into a massive leviathan with a resort on her back. However, Vania's lack of focus resulted in her serving Falfa and Shalsha spicy food, causing them discomfort. On the way back, she and Vania swapped roles, which turned out to be a poor decision when Van remembered a joke that made her burst into laughter, causing the entire resort to shake.

Appearance
Fatla, being a twin, bears an uncanny resemblance to her sister. Her human form is mostly human-like, with a slender yet curvaceous body and stunning features. However, her distinguishing characteristic is the pair of fish-like wings on her crown. Her straight hair is deep blue in color and flows down to her waist. Unlike her sister, Fatla's hair is not parted in the middle but rather features bangs that cover her right eye.

Her attire consists of a long shirt dress with vertical stripes, a tie, and a formal jacket with puffed shoulders and large white cuffs. The jacket is open from the collar to the navel, which allows her ample breasts to be on full display.

As a Leviathan, she possesses the ability to transform into a colossal beast just like her sister. It is described as something incredibly massive, beyond measure, even blocking the sun. Presumably, the creature is too big to comprehend.

Personality
Unlike Vania, who tends to cause trouble, Fatla is a serious and responsible sister who takes charge and keeps things under control. Despite their differences, including Vania's overly carefree and uncooperative behavior at work, they work well together. While Fatla's stoic demeanor can make her seem cold and aloof at times, both sisters are loyal subordinates to Beelzebub and are willing to do whatever it takes to fulfill their duties.

Powers & Abilities
So far, there is no evidence of any other abilities demonstrated by her, except for her appearance alongside her sister as enormous Leviathans while transporting Azusa and company to and from the Demon Realm. Although they can fly in these gigantic forms, it remains uncertain whether they possess the same ability in their human forms.

On the occasion when she, along with Fatla and Beelzebub, discovered Azusa, Laika, and Flatorte battling a group of beasts near a town, she displayed her culinary prowess by expertly cooking the beasts' meat with limited resources. She only had access to a box containing a series of utensils and spices, yet she managed to prepare the dish with exceptional skill.

Trivia

 * The Leviathan is a sea creature in Judeo-Christian folklore, appearing in several Hebrew books, that being Job, Isaiah and Enoch as well as several Psalms. It is serpent-like, capable of breathing fire (breathing fire was symbolism of Hell residing in a creature) and possessing indestructible scales as described in the books, and in Christianity is identified as one of the Seven Princes of Hell
 * The Book of Isaiah 27:1 and later Jewish sources describes the Leviathan as a dragon, which is alluded to in the chapter she debuts in, where Shalsha informs Azusa of the theory that Leviathans may be or related to dragons
 * Similarly, Azusa's misapprehension about Leviathan's being sea creatures is corrected when Beelzebub informs her that they submerge themselves when on vacation, likely the origin of the impression.