Kirby takes a few step running start and then dives forward, shoulder first, and starts his rolling around on his back! He usually burps before he gets to the living room to do his dive...right over his food bowl or on his way away from it is his place to belch! We'd wondered if it was a Corgi thing or not!
Griffyn does this too....usually after eating he runs to the carpeted tv area. While he is running his shoulder hits the ground first and then his face and he ends up on his back rolling back and forth. I call it " the happy boy" dance, and when I say that he continues to do it!