Hela is a character from Norse mythology. She is the daughter of Loki and the goddess of the underworld. You know how when you go to bed, you might dream about scary things? Well, Hela lives in a scary place called the underworld. It's kind of like a dark, spooky cave where people go when they die.
Hela is often represented as having half of her body being normal and the other half being all spooky and skeleton-like. She's not a very nice person, but she does have an important job - she's in charge of deciding who gets to live in the underworld after they die.
Some stories say that Hela was cast out of the realm of the gods because she was too spooky for them. Other stories say that she was just always that way. Either way, she's an important character in Norse mythology and an interesting symbol of death and the afterlife.