Succubae are one of those creatures most people didn’t think existed for many ages. They claim to have existed since the dinosaurs died out the first time, and bear a strong dislike for their egg-based fetishes. They’re a difficult creature to reconcile with our materialistic notion of life, since they’re not from this plane of existence, and largely take physical bodies to play with their food.
To themselves, they are people. They have souls, minds, wills, personalities. Things that evolved don’t. Things that evolved, including triclopes and humans, are chemical soup in attractive packaging. You’re shaped like a person in the way that a chicken nugget might be shaped like an egg. They hate eggs.
What exactly disqualifies all intelligent life from being people is hazy. You might imagine that an entity that had to eat other sentient entities to survive might insist those entities weren’t people in order to assuage guilt. Succubae claim to never experience guilt. Guilt is a chemical thing.