08/18/2011 at 09:00 AM EDT
Well, what do we have here?
The cast of FX's It's Always Sunny in Philadelphia
is kicking off its upcoming seventh season with the addition of a furry feline costar.
In a newly released promotional photo, Charlie Day
, who plays Charlie Kelly on the show, happily poses with one of his character's many cat companions displaying the famed Kitten Mittens
The portrait also gives fans a good look at costar Rob McElhenney's 50 lb. weight gain
, which the actor underwent to expand his character Mac's comedic story lines. "It's been disgusting to watch him go through with this adventure," Day said. "But it has definitely made Mac a lot funnier."
It's Always Sunny in Philadelphia
, which also stars daddy-to-be
Glenn Howerton, Danny DeVito and McElhenney's real-life wife
Kaitlin Olson, returns Sept. 15 on FX.