Deep in the marshes the Tree of Cognizance feeds on whatever living creatures come near it, using very powerful illusions and brute strength. It’s fruits are prized by those that understand the powers they offer.
Evil gives birth to many foul creatures, of these creatures the Negasek have emerged from a womb of darkness and terror. These powerful insect-like creatures radiate the dark force that gave birth to them, born of sheer negative energy, nearly dripping with the foulness of their diabolic nature.
A character who is undergoing changes of personality (like buying off mental disadvantages - flaws - or changing alignment) might confront personifications of aspects of his personality in dreams: a griffon representing the courage he needs to face a terrible foe, or a satyr standing for the lecherousness a warrior must overcome to be admitted to an order of knights who must uphold vows of chastity.