Originally cunning and ruthless in the world of business, Xanatos' meeting with the gargoyles has changed him greatly. 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. 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; in short he values loyalty immediately before anything else.) After the birth of his son, Alexander, Xanatos greatly reformed and gave the gargoyles back their ancestral home as a reward for saving his son from Oberon and the attempted genocide by Demona during Hunter's Moon.
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 their old home in the castle, 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 his robotic Steel Clan he used during battle against the gargoyles. He has a short beard and ties his brown hair in a loose ponytail.
- 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.
- David Xanatos at GargWiki