Washington State coach Mike Leach is the new head coach at Mississippi State, Bulldogs athletic director John Cohen Thursday.

"Mike Leach is a proven winner who has established a culture of excellence for nearly two decades as a head coach," Cohen said in a statement. "An offensive genius and two-time national coach of the year, he has a track record of building programs to national prominence with accountability and a blue-collar approach. We are thrilled to welcome him and his family to the Mississippi State family and look forward to watching our football program grow under his leadership."

The deal is done. See you back in StarkVegas at Bryan Field at 3:15 PM with @Coach_Leach! #HailState pic.twitter.com/qMM06Hz29A

— John Cohen (@JohnCohenAD) January 9, 2020

Washington State coaches were informed about Leach's move on Thursday morning, a source told ESPN.

"I can't tell you how excited I am to be the head football coach of the Mississippi State Bulldogs," Leach said in a statement. "I loved Washington State, but I am excited for the next chapter in the SEC. It's a privilege to be a part of the MSU family, and we look forward to getting down to Starkville shortly."

Leach had agreed in principle to a one-year contract extension through the 2024 season on Dec. 5, prior to the Cougars' appearance in the Cheez-It Bowl.

Before accepting the job at Mississippi State, Leach talked to Arkansas about its opening, sources told ESPN's Chris Low, and was close to landing the Tennessee job two years ago before John Currie was fired as the Volunteers' athletic director.

Leach will succeed Joe Moorhead, who was fired Jan. 3 after going 14-12 in two seasons with the Bulldogs. His stint ended with a 38-28 loss to Louisville in the Franklin American Mortgage Music City Bowl.

Sources said school officials were not only upset by the team's performance in the Music City Bowl, but also with the situation involving starting quarterback Garrett Shrader, who missed the game with an eye injury reportedly sustained during a scuffle at practice.

Overall, in 18 seasons, Leach, a two-time national coach of the year, has taken his teams to 16 bowls and his "Air Raid" passing attack has led FBS 10 times.

Leach went 55-47 in his eight seasons in Pullman and took the Cougars to a school-record five consecutive bowl games over the past five seasons. After a school-record 11-win season and a No. 10 national ranking in 2018, the Cougars went 6-7 in 2019, capped by a 31-21 loss to Air Force in the Cheez-It Bowl.

Prior to Leach's arrival, Wazzu did not appear in a bowl game for eight straight seasons and had won just nine games in four years under previous coach Paul Wulff.

Leach's 43 wins since 2015 marks the most for a Washington State coach during a five-year span. The Cougars have led the FBS in passing offense four times in the past seven seasons. In 10 seasons as the head coach at Texas Tech (2000-09), Leach guided the Red Raiders to a 84-43 record.

Among those to welcome Leach to his new job on social media was Lane Kiffin, the new coach for rival Ole Miss.

Welcome to the state old pirate and friend!! ⁦@Coach_Leach⁩ ⁦@SEC⁩ #swingursword #eggbowl https://t.co/4r4hUsOoC9

— Lane Kiffin (@Lane_Kiffin) January 9, 2020

Mississippi State visits Ole Miss in the Egg Bowl on Nov. 26. The annual game is traditionally played on Thanksgiving night.

Leach's new job also comes with an immediate, if not unusual, home-field advantage.

Earlier this season, Leach, as part of College Football's 150th anniversary celebration, was asked what was the worst visitors' locker room that he's ever been in. Without hesitation, he answered: "Mississippi State."

He described a locker room in which the walls, floor and ceiling were all concrete, and "there was no furniture, there was no benches, there was no lockers." In addition to 37 nails in the wall, Leach said there were two toilets, side by side and without seats, in the middle of the locker room. Between them: one roll of toilet paper.

"The ultimate touch of brilliance," Leach said.