- “Pay a man enough and he'll walk barefoot into hell.”
- ―David Xanatos
Born to Petros Xanatos a fisherman from Maine. At a young age he received a letter containing a coin from the 10th century. Being worth $20,000 he sold the coin and invested the money into various stocks and founded Xanatos Enterprises. Due to his father's belief that his fortune was unearned, their relationship became strained.
Xanatos's holdings include Xanatos Enterprises, a genetics company Gen-U-Tech, the Scarab Corporation robotics firm, and the television franchise Pack Media Studios. Despite his father's belief that Xanatos did not deserve the gift that had launched his career, Xanatos continued to claim that he would one day prove himself a self-made man.
Xanatos learned of Castle Wyvern from Demona, the only remaining Gargoyle from the Wyvern Clan, and proceeded to purchase the castle and transport it, brick by brick, and reconstruct it atop his New York skyscraper, the Eyrie Building. With the castle "above the clouds," Xanatos successfully released the survivors of the Wyvern Clan from their frozen sleep.
Xanatos initially posed as the Gargoyles' friend, convincing them to "acquire" technology from his rival Cyberbiotics for him and ultimately attempting to destroy the gargoyles once their replacements, the Steel Clan, came online. The Steel Clan was defeated, however, and Xanatos was convicted for receiving stolen property. Xanatos continued to plot against the gargoyles from prison, testing them and attempting to remove them from the castle. Upon his release, he became one of their greatest enemies, engaging in a particularly fierce rivalry with their leader, Goliath.
Xanatos also committed himself to getting his own clan of gargoyles that would be loyal and obedient to him. To that end, he tried several attempts throughout the series to do that such as resurrecting Goliath's brother, Coldstone, from the smashed bodies of three dead gargoyles from the Scottish clan; genetically creating his own clan of mutant gargoyles, one of whom was Elisa Maza's brother, Derek Maza; creating a clone of Goliath, and perfecting the Steel Clan. When these attempts failed, he changed focus to continuing his quest for immortality but by using sorcery, magic, and even involving himself with Children of Oberon, the King of the mystical island Avalon, instead.
Cunning and ruthless in the world of business, Xanatos is a master planner, even letting supposed failures further his various goals. He at first tried teaming up with Demona to control them with his Steel Clan but was forced to end their partnership when she double-crossed him.
Despite these setbacks, Xanatos makes a point to never take them personally since he considers pursuing revenge foolish and beneath him. In fact, Xanatos rarely fails completely in his schemes considering he is notorious for complex plans that often produce desired results in some aspect regardless of the opposition.
After marrying Fox, the leader of the Pack, Xanatos had become less interested in the gargoyles and more interested in finding immortality for himself and his wife. However, all his futile attempts ended in vain. He displays an odd sense of choice, given he would take a lifetime of servitude from Owen over a magic wish from his alter-ego Puck. (Xanatos saw having a life-long loyal right-hand man much more beneficial than taking a shortcut to achieve his goal of immortality, which he was confident of achieving through other means anyway; in short, he values loyalty immediately before anything else.)
In the three-part episode "Hunter's Moon", when the Clock Tower was destroyed by the Hunters and the gargoyles subsequently trapped by the Gargoyle Taskforce at Saint Damien's Cathedral, Xanatos rescued Goliath's clan and offered them to reinstate in their old home in the castle, for saving the world and his son from the attempted genocide by Demona during Hunter's Moon, with "no catch, no plot, no strings". The feud was over.
Xanatos normally dresses in a casual black suit, but in his early scuffles with the gargoyles, he would don a red exo-frame modeled after Goliath that was part of the robotic Steel Clan he used during battle against the gargoyles. He has a short beard and ties his brown hair in a loose ponytail.
- The non-canon third season, titled The Goliath Chronicles, portrays Xanatos as a benefactor and friend of the clan, having truly redeemed himself after they saved his son’s life.
- Xanatos is one of several characters played by a Star Trek cast member - in this case, Jonathan Frakes, who portrayed William Riker.
- During the show's development, Xanatos was originally known as Xavier and he was the descendant of the wizard that originally cursed the gargoyles to sleep for a thousand years. According to Greg Weisman, he was "rich, powerful, and petulant. Very Captain Hook."
- This idea of a descendant of an ancient enemy was eventually used for Wolf and Hakon in "Vendettas."
- The name Xavier was eventually dropped because of the similarity to Professor X (Charles Xavier) in Marvel Comics X-Men. Still, Greg Weisman wanted a name with a similar sound to it.
- Thinking of Thanatos, the Ancient Greek God of Death, and since X and TH sounds are often interchanged, he tried the name Xanatos, which was quickly accepted by other crew members.
- Sometime later, he checked the phone book and found that Xanatos was in fact a real name.
- Weissman chose Xanatos' first name to be David as Goliath was his former enemy, a reference to the biblical story of David & Goliath except with the roles of hero and villain reversed.
- Odysseus was also in Greg Weisman's mind when developing Xanatos into a human trickster, particularly when the character became Greek-American.
- Coincidentally, Jonathan Frakes' wife, Genie Francis, was expecting at the same time as Fox.
- Xanatos is the namesake for the prominent term "Xanatos Gambit" featured on the website TV Tropes, which refers to extremely well-coordinated plans where alternative outcomes will still somehow benefit the mastermind even if they do not conventionally "win". There used to be a number of other tropes about master plans and "gambits" bearing Xanatos' name, but these have since been renamed with the exception of the original term.
- In the original comedy treatment, a billionaire moved the castle for the simple reason that he could.
- In the Goliath Chronicles episode "For It May Come True", Titania created a world where Goliath was human. Xanatos remained an enemy of the Manhattan Clan possibly because they didn't save his son from Oberon (it was at Goliath's request that they save him). This is non-canon.