Rob McElhenney thought it'd be weirdly funny if he gained fifty pounds for Season 7 of 'It's Always Sunny in Philadelphia.' He was right: the mere sight of the previously fit, now very Fat Mac proved instantly hilarious when an on-set picture of McElhenney surfaced and went viral a few weeks ago.

Now we're getting a first look at a teaser trailer for the new fall season, and Mac's weight gain is taking center stage. Actually, it's taking up the entire stage.

In the trailer, Mac progresses from sobbing into an oversized bowl of cereal to laying in a hospital bed surrounded by the gang, clutching a plate of cookies for dear life.

Check out the trailer after the jump.