This is my interpretation of fearlings from Guardians of Childhood.

While nightmare sand just gives people nightmares, they can’t really harm humans once awake and nightmares can be forgotten or even enjoyed once awake.

With fearlings, I like to think that they not only feed on fear, but hate, deception, greed, basically all evils that cause a species’ self destruction. I know in the book they’re depicted as like shadow, but I see them as having a more tar consistency.

With individual fearlings taking the form of a fear or phobia and having a more solidified form, but as fearlings get bigger and molded by more phobias and more fearlings they start to lose their solid state and look like their melting.