By now, everybody has seen the picture. A tan dog in a tactical vest, sitting up at the position of attention, perky ears framing a black face. The mouth wide open, the tongue hanging out the side of the mouth, the dog looks happy, almost goofy.
This is the dog that chased down ISIS leader Abu Bakr al-Baghdadi this past weekend, leading to al-Baghdadi’s death when he detonated a suicide vest he was wearing. The dog was injured in the blast, but has since returned to duty. Assigned to Delta Force, the dog’s identity is classified, even as the dog is being hailed as a hero, with the picture shared on Twitter by President Donald Trump, who called it Conan.
Read on to find out what we know about this dog.

U.S. Marine military working dog Argo rides into the ocean on a combat rubber raiding craft at Red Beach.
(US Marine Corps photo by Lance Cpl. Andrew Cortez)
They are the special forces of military working dogs, attached to special operations forces, such as the Navy SEALS and Army Rangers. Trained to find explosives, chase down human targets, and detect hidden threats, these Multi-Purpose Canines, or MPCs, are also trained to rappel out of helicopters, parachute out of airplanes, and conduct amphibious operations on Zodiac boats. Highly skilled, an MPC named Cairo even assisted in the raid that killed Osama bin Laden in 2011.
These dogs are specially selected and trained to handle the most stressful situations while keeping their cool. In the spirit of the Marine Recon motto, these dogs are swift, silent, and deadly. Barking is forbidden. With the secretive nature of their work, much of the information regarding the selection and training of these dogs is classified.

A military working dog chases a suspect during a demonstration.
(Air Force photo by Airman 1st Class Jacob Derry)
Four times per year, a team of canine handlers, trainers, veterinarians, and other specialists from the 341st Training Squadron at Lackland Air Force Base in San Antonio Texas — the home of the Military Working Dog Program — make the trip abroad to buy dogs. They evaluate each dog to ensure that they will not have any medical issue that will prevent them from serving for at least 10 years. They perform x-rays to ensure that there is no hip or elbow dysplasia or other skeletal defects. Dogs with skin conditions, eye issues, or ear problems are ruled out.
If they pass the medical screening, they are further assessed on their temperament. Over up to 10 days, the dogs are judged on their ability to search and detect, their aggressiveness, and their trainability. While the special forces have their own programs to procure dogs, which are confidential, the traits that they look for are the same. The standards are just higher.

Caro, a five-year-old Belgian Malinois with the 96th Security Forces Squadron, stands by her handler.
(US Air Force photo by Samuel King Jr.)
This hero dog from the al-Baghdadi raid is a Belgian Malinois, one of the most popular breeds among working dogs.
This hero dog from the al-Baghdadi raid is a Belgian Malinois, one of the most popular breeds among working dogs. W
While the military uses labs, retrievers, and other breeds including a Jack Russell or two for detection, the most popular breeds of war dogs are Belgian Malinois, Dutch Shepherd, and the ever popular German Shepherd. These dogs are valued for their intelligence, trainability, work ethic, and adaptability.
The Malinois in particular is valued for its targeted aggression, speed, agility, and ability to survive in extreme heat. Handlers are known to refer to their dogs as either a “fur missile” or a “maligator.”

A Multi-Purpose Canine with U.S. Marine Corps Forces Special Operations Command (MARSOC), prepares for Zodiac boat training inserts on Camp Pendleton, Calif.
(US Marine Corps photo by Sgt. Maricela M. Bryant)
The dogs are hand selected from the best kennels in Europe and around the world, brought to the United States, and trained to the highest level.
They are taught patrolling, searching, explosive or narcotic detection, tracking, and are desensitized to the types of equipment around which they will work. They are familiarized with gunfire, rappelling out of helicopters, riding in Zodiac boats, or even skydiving. All said, the dogs and their training cost up to ,000 each. Including the highly specialized gear of MPCs, the cost can be tens of thousands of dollars higher.
Wearing bulletproof vests outfitted with lights, cameras, communications equipment, and sensors, the dogs can operate off leash, providing a real-time view to the handler while taking verbal commands through the radio.

A Multi-Purpose Canine handler with U.S. Marine Corps Forces, Special Operations Command prepares his canine for a parachute jump.
(US Marine Corps photo by Sgt. Scott Achtemeier)
Over their years of service, a multipurpose canine will conduct dozens of combat missions over multiple deployments, most of which the public will never hear about.
One of these missions resulted in the death of Maiko, a multi-purpose canine with the Army’s 75th Ranger Regiment. Leading the way into a secure compound in Afghanistan in November 2018, Maiko caused the Al Qaeda fighters to open fire, giving away their position, allowing the Rangers to eliminate the threat without injury.

A multi-purpose canine handler with U.S. Marine Corps Forces, Special Operations Command, checks for a pulse while administering medical care to a realistic canine mannequin.
(US Marine Corps photo by Cpl. Bryann K. Whitley)
When dogs are injured on the battlefield, their handlers are trained to provide first aid.
Using specially developed, highly realistic dog mannequins, the handlers are trained to treat massive bleeding, collapsed lungs, amputations, and more. The mannequins respond by whimpering and barking.
Many of the developers of this dog mannequin came from the Hollywood special effects world, working on productions like the Star Wars or Harry Potter films. The simulated dog, with its pulse and breathing responding to the treatment, costs more than ,000.

Military working dog handlers with the U.S. Army Rangers and U.S. Marine Corps Forces Special Operations Command multipurpose canine handlers fast-rope from a U.S. Navy MH-60 Seahawk helicopter.
(US Marine Corps photo by Lance Cpl. Drake Nickels)
If a dog is injured in combat or in training, or is showing signs of Post-Traumatic Stress Disorder, he can be sent to a dog hospital at Lackland Air Force Base for surgery, rehabilitation, or assessment for retirement.
While PTSD is not well understood in dogs, veterinarians, dog trainers, and specialists at Lackland Air Force Base agree that dogs show symptoms of combat stress as much as humans do. Whether they become fearful of loud noises, become more aggressive, forget how to do tasks, or decide that they don’t want to work, these dogs are rehabilitated with the goal of returning them to service. If this is not possible, the dogs are evaluated for transfer to non-combat jobs or potential retirement.

Nero proudly displays his U.S. Military Working Dog Medal during his retirement ceremony aboard Marine Corps Base Camp Pendleton, Calif. on May 21, 2018. During his five years of service, Nero served two deployments. Nero will be adopted and spend his retirement as a companion to his handler.
(US Marine Corps photo by Cpl. Bryann K. Whitley)
Before being retired, the dogs are assessed to ensure that they do not pose a risk to the public.
After up to a decade of devoted service, the goal is to let the dog live out its life on a soft bed, preferably with one of its former handlers.
This article originally appeared on Insider. Follow @thisisinsider on Twitter.