How did the Chicago Cubs and Arizona D-Backs kill time during 2 1/2 hours of rain delays??

EPIC BULLPEN DANCE-OFF!!

Both teams took the competition from the diamond to the bullpen while waiting out the weather at Wrigley Field Thursday night ... and the results are absolutely hilarious.

Human Bowling? Check. Human Fishing? Yup. Upside down dancing man? Better believe it.

The Cubs even brought out animal masks for their act ... so you know there was some planning involved.

Once they finally got back to baseball, the D-Backs topped the Cubbies 10-8.