Back on track with The Mimic,Rin Tsushima (human form) or known as her monster name,Futakuchi-Onna
If you havent played The Mimic yet,STOP reading! :warning:

This is the part where Rin's anger and jealousy overtake her,as she thinks her sister Mio as been going around eating well (they were raised in poverty and most of the time had to starve) without her.So,overtaken by those emotions,she consumes her own sister,Mio.But in reality,turns out her sister was saving money for both.