Leonard Snart

Leonard Snart, nicknamed Captain Cold by Cisco Ramon, is a bank robber from Central City.

Early life
Snart's father was a corrupt police officer who took his anger out on him and his sister until he was sent to prison. When he was a kid, his grandfather took him and his sister to a diner right across from Central City Precinct named the Motorcar. Snart kept going there in his later life to listen to police radios and learn their response times. He dropped out of high school and eventually became a bank robber, putting together a crew. Every six months or so, he arrived in Central City to case a job for a few weeks, and disappeared after stealing his target. He became one of Central City's Most Wanted. He worked on a job with Mick, which ended badly for the latter, and Snart ended the partnership between the two.

Kahndaq Dynasty Diamond heist
In 2014, Snart, along with his crew, attempted to hijack an armored car in order to steal the Kahndaq Dynasty Diamond it was carrying to an exhibition in the Central City Museum. They stopped the armored car by hooking it to the tow truck they brought to the robbery via steel cables. After taking the security guards as hostages, Snart opened the door of the armored car by using liquid nitrogen on it, just before the Flash arrived at the scene. The Flash quickly took down the robbers, making Snart lower his mask and expose his face to the metahuman. One of the security guards was shot in the shoulder by one of Snart's men, forcing the Flash to take him to a hospital as Snart and his crew escaped.

Back at their base of operations, Snart looked at the camera footage of the robbery he stole from the armored car as his men argued about what the Flash was, with one of them stating maybe it was a top secret drone. Snart explained that they attacked moving targets because the police response time was a hundred eighty two seconds once the armored car reported the robbery, as opposed to sixty seconds with banks. He berated his man who shot the security guard for "losing his cool" when the Flash had arrived. When the man said he was quitting, Snart killed him by shooting him in the back. He claimed that the Flash was a man, and they needed to "up their game." Snart later met with the arms dealer Basil Nurblin. Nurblin first offered Snart a fire-based weapon but Snart refused, saying "he did not need to heat things up, but slow them down." Next, Snart looked at a weapon stolen from the S.T.A.R. Labs that emitted a cold substance and glasses meant to protect against the glare the weapon caused. Snart asked Nurblin who else knew he had taken the weapon, and when Nurblin answered they were the only two, Snart shot and killed him with his newly acquired weapon.

After obtaining his cold gun, Snart went to the Central City Museum to observe the security around the diamond he had tried to steal earlier. By taking the exhibit tour twice, he alerted the museum owner Dexter Myles, who contacted Detective Joe West, who followed Snart after leaving the museum. When the detective caught up to him, Snart used the cold gun to freeze the road underneath a newly arriving police car, and escaped into a nearby theater as the car crashed. Inside, Snart shot at Detective West, but the Flash managed to get there in time to throw the detective out of the way, instead being hit by the weapon himself. Snart then started shooting at the nearby civilians, forcing the Flash to save them, as a test run. The Flash managed to save all but one of the civilians, but was unable to get to the theater's security guard in time as he was slowed down by the cold gun. Snart left the scene when the Flash was distracted by the deceased security guard. Returning again to his base, Snart told his remaining two men they would be back to the museum to steal the diamond that night. When his men protested, saying the museum would be crawling with the police and the Flash, Snart answered his cold gun could stop the Flash and he knew the Flash's real weakness. His men mutinied and pulled a gun to his head. They left, saying the Central City was no longer Snart's playground now that the Flash was there. Disagreeing with them, Snart went to the museum by himself and broke in using the cold gun. He successfully stole the diamond and made his way to the Central City Train Station where he was engaged in a gunfight with Detectives West and Eddie Thawne. Snart escaped the two men by getting on a train, but this time he was challenged by the Flash who had followed him using a signal the cold gun emitted. He told the Flash that he had seen his real weakness during the armored car robbery and at the theater. Saying he would save himself while the Flash saved everyone else, he shot the floor of the train with the cold gun and jumped from the train before it was derailed. The Flash managed to get everyone out of the train, but was ambushed by Snart who shot him in the back with the cold gun. He thanked the Flash for forcing him to up his game, before he was threatened by Cisco Ramon with the prototype of the cold gun which was actually just a vacuum cleaner with LED lights. When Ramon called him Captain Cold, he smiled and left, taking the diamond with him.

Snart discovered and disabled the signal his gun emitted with which the Flash had tracked him. He met with his former accomplice Mick and told him even though their previous partnership had not worked out well, things had changed and that he needed a new kind of crew. He offered Mick the fire weapon he had taken from Nurblin, and asked if Mick wanted to join with him, which Mick accepted.

Personality
Snart is a ruthless man who exudes a calm and chilling disposition, seldom ever losing his temper or giving into emotions. Although he never finished high school, he is intelligent and patient, staking out a job for months before making his move, emphasizing timing, precision, and minimizing possible leads on him and his activities by refusing to kill unless necessary. He was also clever enough to deduce that what stopped his job at the armored car was in fact a man, and that he would need a weapon to halt Barry, choosing the cold gun for this very reason. Snart has however begun to revel in his new-found weapon's power, and his battles with The Flash have begun to alter his perceptions of how the job works.

Abilities

 * Tactical Analysis: Snart is highly intelligent, planning every detail of his heists, down to the last second. He also possessed enough cunning to upgrade his methods, knowing he could not defeat the Flash on his own, without help. His skill was so high, he was able to defeat Barry Allen twice, despite being just a normal human.
 * Thievery: Over years of criminal experience, Snart has mastered the art of thieving, from armored car heists, jewel theft and bank robbery, he displays the utmost skill.
 * Marksmanship: Snart has the skill to hit The Flash with a blast from his freeze pistol, despite the former moving at superhuman speed.

Equipment

 * Cold Gun: Can generate a beam of absolute zero temperature, freezing whatever it touches and creating solid objects of ice. It can also slow down the motion of The Flash's molecules, retarding his accelerated healing and vastly reducing his speed. It also gives off bright white flashes.
 * Goggles: Snart also wears a pair of blue wraparound goggles, which are designed to protect his eyes from the flashes given off by his cold gun.

Trivia

 * In comparison with some of his DC comic book portrayals, this version of Leonard Snart is more serious, and a genuine threat to Barry Allen's life.
 * In the episode, Snart wears a blue parka along with his goggles towards the end of the episode. This is a reference to his costume in the DC comics.