The Sentinels are a group of mutant-hunting robots appearing in American comic books published by Marvel Comics. They are typically depicted as antagonists to the X-Men. The Sentinels played a large role in the 1990s X-Men animated series and have been featured in several X-Men video games. The Sentinels are featured prominently in the 2014 film X-Men: Days of Future Past while simulated versions made brief appearances in the 2006 film X-Men: The Last Stand and the 2016 film X-Men: Apocalypse. In 2009, The Sentinels were ranked as IGNs 38th Greatest Comic Book Villain of All Time. Publication history Created by Stan Lee and Jack Kirby, they first appeared in The X-Men #14 (Nov. 1965). Sentinels are programmed to locate mutants and capture or kill them. Though several types of Sentinels have been introduced, the typical Sentinel is three stories tall, is capable of flight, projects energy blasts, and can detect mutants. Pursuing genocide as the means of dealing with a threat has made the Sentinels an analogy for racial hatred and other negative types of fanaticism in Marvel stories, represent the horrific consequences of humanity's actions based on hate and ignorance, along with a caution of the risks of AI takeover. Characteristics Sentinels are designed to hunt mutants. While many are capable of tactical thought, only a handful are self-aware. Sentinels are technologically advanced, and have exhibited a wide variety of abilities. They are armed (primarily with energy weapons and restraining devices), capable of flight, and can detect mutants at long range. They possess vast physical strength, and their bodies are highly resistant to damage. Some are able to alter their physical forms or re-assemble and reactivate themselves after they have been destroyed. Some Sentinel variants have the ability to learn from their experiences, developing their defenses during an engagement. Several groups of Sentinels have been created and/or led by a single massive Sentinel called Master Mold. Some Sentinels are also equipped with an inconspicuous logic loop in case they should go rogue to convince them that they are mutants as demonstrated in the Tri-Sentinel. Because of their power, sophistication, and high mass production, Sentinels are sold on the black market. Entities obtain them—often in poor condition—for their own purposes (not necessarily mutant-related). During the "Iron Man 2020" event, a Sentinel appears as a member of the A.I. Army. Types of Sentinels There are different types of Sentinels that