Eldriathans

The term Eldriathan is a combination of the words eldritch and Leviathan.

Eldriathans are gigantic monsters of The Nothingness that are made of tar, eyes, and bones. They tend to resemble various aquatic creatures, including amphibious ones. The most common appearance for Eldriathans tend to be marine animals in particular, especially those that can be found in the deepest parts of the ocean.

Abilities
They 'swim' through the Nothingness, usually the part that is always beneath Stories. They travel around and feed by observing the happenings of a Story. Some Eldriathans prefer Stories of a certain "mood", such as a more hopeful Story versus a more grim Story. In general it seems that most Eldriathans prefer Stories with a darker tone, as it is said that these "taste better" than 'lighter' Stories.

Unfortunately, these beings can also manipulate Stories into becoming more "grimdark" in order to make them more tasty. Some of them are so powerful that even just being near a Story will make it more grimdark, without any active manipulation from the Eldriathan. Part of Doña Sapphira's job is to make sure Eldriathans do not end up intentionally feeding off of any particular Story too much or too often, and to keep their grimdark manipulations to a minimum. This is because She's the only person in the Janitor Menagerie who is strong enough to fight back against them. Most Eldriathans in the area under the Doña's protection know not to get on Her bad side, though (Shanty) is the only one who still fights back against Her, even though Shanty has been beaten many times by now.

Besides their grimdark influences, Eldriathans are also physically strong due to their immense size, and can weaponize the tar and bones that composes their bodies in order to harm and trap others. Their eyes can also cause various magical effects, from damaging fireballs to confusion illusions. Though they do not need to eat like normal living beings, they will be more than happy to eat or kill someone who's bothering them.

Hub World
There is a plane of existence below the Nothingness called Arcasteryss (arcane + mystery + abyss) where Eldriathans seem to originate from. It is described as being very dark, "almost too dark", but not much else is known about it. Some Scrivenions have attempted to travel to this plane to record information about it, but unfortunately none have returned. Attempts have also been made to interview an Eldriathan directly about Arcasteryss, but even the most friendly Eldriathan tend to be very wary of giving any information about it. Supposedly the Doña was able to get this information at some point, but it is most likely a highly guarded secret in the Ideasphere by now.