Katy Perry -- My Limo Driver Made My Music Video Doggone Awesome

Katy Perry should give her limo driver a 10% cut of profits from her new video ... because he's the one who discovered the biggest breakout music video star since Courteney Cox.

Jiff the Pomeranian steals the show ... and credit goes to the guy who was sitting behind the wheel last month while Katy was at the Grammys.

We're told the driver noticed the tiny pooch doing skateboard tricks and he was good enough to attract a crowd. The driver shot video of the pup and even took a flyer from the dog's owner which included contact info.

When the Grammys were over Katy got in the car and she and the driver started small-talking. She asked what the driver had done to pass the time ... he showed her the video of the dog.

Two days later ... Katy's people took the flyer from the driver -- he wisely saved it -- and made a deal with the dog's owner.

So now Jiff is a big dog ... a star in his own right. And we're told Katy says she will work with him again.

So congratulations limo driver. You're a big dog, too.