Monkey King

"I know this sounds crazy, but I had to help John to slay the Monkey King. It tried to eviscerate an entire family. I saved the kids' lives, but I had to sacrifice one of my own."

- Chas Chandler to Renee Chandler.

The Monkey King was a malevolent entity slain by John Constantine with the help of Chas Chandler.

Biography
At some point between 2012 and 2014 The Monkey King tried to eviscerate an entire family. John Constantine interrupted, slaying Monkey King with the help of Chas Chandler who lost one of his souls as a result, as well as missing the birthday of his daughter, Geraldine Chandler. The latter eventually led to him divorcing with Renee Chandler.

Behind the scenes

 * In the DC comics, the entity known as The Monkey King is Kamara, an entity of fear that fed upon the terror of others. It is notable that it was an antagonist in the comic Swamp Thing #25, which was also the very first appearance of John Constantine.