Wiktionary
n. (context with "the" English) The unchangeable nature of something.
Wikipedia
Nature of the Beast is a television film starring Autumn Reeser and Eddie Kaye Thomas. It premiered on ABC Family in 2007. It was directed by Rodman Flender. This television film was shot in Toronto, Ontario.
"Nature of the Beast" is the first episode of the ninth season of the American police procedural drama NCIS, and the 187th episode overall. It originally aired on CBS in the United States on September 20, 2011. The episode is written by Gary Glasberg and directed by Tony Wharmby, and was seen by 19.96 million viewers.
In the episode, Special agent Tony DiNozzo is shot and unable to remember what it all was about. He must work together with Special agent Leroy Jethro Gibbs and Dr. Rachel Cranston to identify the attacker.
Scott Wolf is introduced as FBI agent Stratton, while Matthew Willig's NCIS Special agent Simon Cade is shot dead.
Usage examples of "nature of the beast".
None could surmise the nature of the beast that slew and ravened in such fashion.
In these two novels, classics since their publication, he explores the nature of man, the nature of the beast, and the nature of Jack London.
An old conclusion still seemed the only answer he could see: It was, and is, the nature of the beast.
As the soft-cyber unit selected the nearest approximate meaning to what the user meant, the name would probably reflect the nature of the beast.