Charlie Day on "It's Always Sunny in Philadelphia." FXX With the 12th season of FXX's "It's Always Sunny in Philadelphia" set to premiere in 2017, actor Charlie Day has given fans a brief preview of things to come on the hit comedy.

Day recently told Red Carpet Roxy that fans of the show can expect a "funny year," filled with a few promising premises.

"You can expect to see some of the UFC, you can expect to see an entire musical episode, guest starring from Scott Bakula," Day said. "You can expect to see us at a water park, you can expect a very funny season."

The show is no stranger to musical numbers. One of its most memorable episodes, "The Nightman Cometh," was a musical that even spawned a live tour in 2009, featuring the rock opera music written by Day's character.

"Always Sunny" was renewed by FXX earlier this year and will run for a 13th and 14th season following its upcoming one in 2017.