DENVER, CO — Denver firefighters found a big snake slithering out of a car over the weekend while they were checking up on a driver sleeping inside. The snake crawled out the driver’s side window and onto the roof.

The 15-foot snake was a pet, the department said. The car was found in the Denver’s Green Valley Ranch neighborhood.

The snake’s owner had been drinking and was passed out behind the wheel, according to the Denver Fire Department.

“Don’t drink & drive, especially with your pet snake in the car!” the department tweeted.