Here is a bit of a darker but more unique treat for you, the lamp gheist.
In it's simplest form, these creatures feed off life force to sustain themselves, although they typically do not need too.
As it is the easiest way for them to feed, most Lamp Gheists tend to be rather violent, drinking up the fading life force of their victims, and it gives the race overall a bad name.
Play wise, they uniquely exchange Hit Dice for abilities, and then refill HD by fighting. Due to this, they can work well on any heavy damage class or subclass, especially if that build is able to knock down multiple enemies at once. That being said, burning ones own life away for power can lead to some sticky situations where, if your not careful, you may end up with a true lack of health remaining.
As always, let me know what you think and how they play in your own games, and I hope you all have a sweet day ahead.