Derek "Frost" Westbrook

"Frost. Frost! Get switched on. We gotta move, now!"

- Sandman to Frost in "Black Tuesday".

Staff Sergeant Derek "Frost" Westbrook is one the playable characters in Call of Duty: Modern Warfare 3. He is a Delta Force operative and Team Metal member, who is assigned to multiple operations to end World War III.

In Find Makarov: Operation Kingfish, he was portrayed by Justin Major.

Biography
Derek Westbrook joined the United States Army presumably in his youth, rose to the rank of Staff Sergeant, and was nicknamed "Frost". Frost later joined Delta Force, and was sent to Team Metal, a team led by Master Sergeant Sandman, and other members, and Sergeant First Class' Truck and Grinch.

Operation Kingfish
Frost and Sandman participated in Operation Kingish with Captain Price, John "Soap" MacTavish, Simon "Ghost" Riley and Gary "Roach" Sanderson to capture Vladimir Makarov. Frost and Sandman gave support from afar, but realized that it was a trap before heading to extraction. Soap was wounded, and Price stayed behind to fight the Russians for his allies to escape, and was taken to the Gulag.

World War III
Frost participated in World War III, and fought against the Russian Army when they invaded the United States, and attacked the White House. Team Metal went to New York and were assigned to stop a Russian jammer at the Stock Exchange, but Frost and Sandman's vehicle is attacked by Russian soldiers. After leaving the vehicle, Frost and Sandman meet up with Truck and Grinch, and fight their way to the stock exchange. After destroying the jammer on the roof, Team Metal were extracted on a Black Hawk, but had to fight a Russian Hind.

Frost and Team Metal were assigned with Navy SEALs to take control of Oscar II, a Russian submarine that was the command vessel. After swimming through the Brooklyn Battery Tunnel, Frost and Sandman enter the sub and fight Russian soldiers and engineers before making it to the main room. Frost and Sandman then re-program the missiles to launch onto the Russian fleet, and escaped on a zodiac to extraction.

Team Metal were later assigned to Germany to rescue the American Vice President, and were assisted by the U.S. Army Rangers and a armor tank. After Carter was killed by a Russian sniper, Frost took the gunner position, and led the tank through indoor parking lots. After losing the tank, Frost, Sandman, and the tank's crew continue towards the Vice President's convoy. The group succeeded in rescuing the Vice President, and the team were later sent to Paris to capture Makarov's bomb maker, Volk, after getting intel from Captain Price.

Overlord ordered Team Metal to help assist the GIGN led by Sabre, and the group continued to the catacombs and later captured Volk in a car chase. Afterward, the team were attacked by Russian soldiers, and had to get assistance from a AC-130, who destroyed Russian tanks. The Team succeeded in extracting Volk, despite having to go to another extraction point, and the destruction of the Eiffel Tower.

After Captain Price gave the team intel on that Makarov was targeting the Russian president's daughter, Alena Vorshevksy, the group traveled to Berlin. Team Metal were suppose to provide sniper support for Team Granite, but the team were killed in an explosion after breaching the hotel. Sandman and the team volunteered to secure Alena, and fought through the city despite heavily casualties. The team failed to secure Alena, as the door Sandman and Frost were ready to breach, exploded. Frost collected Sandman's sidearm to shoot the Russian soldiers, but were too late to rescue Alena.

Frost wasn't part of the joint operation between Delta Force and Task Force 141, who were assigned to rescue the Russian president and his daughter from a diamond mine. Sandman, Truck and Grinch were presumably killed in the diamond mine, as they protected Captain Price, Yuri and the others to escape.

Trivia

 * He is one of the few playable campaign characters to appear in Special Ops missions.
 * Frost was planned to be in "Down the Rabbit Hole", as unused voice files have Price yelling his nickname and surname.