Abstract spirit

"What does it look like? Well, I guess it's... A dog? I think..."

When the fall of The Curtain merged the material and conceptual world, it also meant changes for the Spirit, the inhabitants of the latter one. For some, their "hunting grounds" became even more abundant in concepts that fed them. For some, nothing changed besides them now being corporeal. And some, especially the ones inhabiting what now became the more unstable parts of The weird wilderness, were suddenly in trouble, as they couldn't feed on what they used to before with their environment constantly changing.
Facing a dilemma of starving or becoming something completely different by eating concepts not related to them, abstract spirits chose the second option.

Appearance

If they're lucky, abstract spirits keep some of their old appearances. Maybe their shape still resembles what they were. Maybe one of their limbs is still the same. But those are just echoes of the past. Other than that, there are no two abstract spirits that will look the same.

Psychology

"Oh, human, yes, I remember humans. Their thoughts _taste^friendship. Such interesting...Oh, human..."

While some abstract spirits manage to accept what they have became, there's something wrong about them. It's like looking at a puzzle where half of the pieces come from different sets and even the right ones are at the wrong places to the point where it is hard to recognize what the original image even was. When talking to one of them, they'll often stop, as if trying to remember something. They might put some unrelated words into their sentences or completely drift off. Sometimes it is like talking with many people at the same time.
Some just go mad. That might save them, turning them into spirits of rage or madness. But most, stay abstract.

Dietary habits

Even when it comes to their diets, those spirits are very varied among themselves. Some will try to eat as little as possible, trying to keep the remains of what they are until they manage to find what they ate in the past. Some will embrace their new diet as a part of what they become. There might even be some curiosity as to what they could become if they'll continue. Some find a balance in just trying new things. Things they have never tried before. And some start to feel a ceaseless, insatiable hunger. The last ones might even turn into new spirits of hunger.

Genetic Ancestor(s)

• Spirit

Origin/Ancestry

Various, mixed

Geographic Distribution

• The weird wilderness

Taboo
The concepts of abstract spirits changed so much that their taboos also got warped. Some spirits become so fragile that almost anything could destroy them. Some become practically invincible. And for some, their taboos just become weird, unrelated to anything. Maybe to destroy them someone has to sprinkle sugar on their tongue while standing on one leg. Maybe they have to wave at them. Maybe the sight of cheese terrifies them now.
Reproduction
Spirits don't reproduce.
Social hierarchy
Among all things, abstract spirits want to return to what they were ( at least as long as they still remember it). That's why a lot of them will search for the spirits of what they were so they can feed on the same concepts as their old brethren. This comes with various responses from said brethren, as many spirits wouldn't want to deal with the abstract ones, either for fear of getting tainted or hatred towards lower, unpure spirits. When dealing with each other, abstract spirits, like with everything else, come in various flavors. They may prefer solitude or fear others like them. They might form groups and herds, even with spirits that are nothing like them. They might kill each other, either because of hatred for what they became or to consume each other.