One It's Always Sunny In Philadelphia Season 16 Plot Comes From The Cast's First Time Meeting Danny DeVito

Frank Reynolds from "It's Always Sunny in Philadelphia" has become a character of almost mythical proportions. He's a business tycoon of some notoriety who hangs out with four degenerates known as "the gang": serial creep Dennis Reynolds (Glenn Howerton), backstabbing wannabe social climber Dee Reynolds (Kaitlin Olson), gay Catholic karate enthusiast Mac (Rob McElhenney), and paint-huffing grub-monster Charlie (Charlie Day). 

Frank was introduced to the series in the second season in order to bring up viewership, because the folks at FX believed that audiences just needed to see a recognizable name in the cast to tune in. Frank and DeVito ended up being the perfect missing piece of the puzzle, turning "It's Always Sunny" from good to great and helping it become the longest-running live-action comedy series in history.

In season 16, episode 2, "Frank Shoots Every Member of the Gang," Charlie and Mac go on a road trip to get Charlie's inheritance: a jar of teeth. The Kelly family has some pretty strange traditions, but this one takes the cake. Who keeps teeth in a jar? 

Well, it turns out that the story was actually inspired by something DeVito told his castmates the very first time they met!  

The first lunch meeting between DeVito, McElhenney, Howerton, and Day has since become something of "It's Always Sunny" legend, shared in bits and pieces by the guys over the years starting with a group appearance on "Conan" in 2015. The guys were understandably nervous about meeting up with the comedy titan, but he burst in "like a tornado" according to Day, and then went about talking their ears off on a variety of topics. 

The one that stood out, however, was a story about a box of teeth that DeVito's father allegedly kept, which also sometimes held wristwatches. In the Conan appearance, DeVito said that he might have been pulling a fast one on his new business partners, but it made enough of an impact that the idea made it into the show itself 15 seasons later. Instead of a box of teeth and timepieces, Charlie is supposed to get a glass jar full of teeth, but the idea is pretty similar.

The guys have also shared the box of teeth story on the "It's Always Sunny" podcast, along with many, many other tales about their experiences with DeVito. The man is as much of a mythical creature as Frank Reynolds, honestly, and hearing the gang talk about him is always pure joy. In one of the best episodes of the podcast, DeVito even came on himself and answered a whole bunch of questions about his time on "Sunny," his long and storied career, and his life in general. For "Sunny" fans, it's a must-listen.

DeVito is a comedy legend, with an acting and directing career that spans more than 50 years. His first major role was in "One Flew Over the Cuckoo's Nest" with Jack Nicholson in 1975, and he became a household name a few years later when he played cab dispatcher Louie DePalma in the 1978 comedy series "Taxi." There's a whole lot of Louie in Frank Reynolds, but I get the feeling there's a fair bit of DeVito in both of them. In the episode of the podcast where DeVito guests, many of his anecdotes and mannerisms are reminiscent of Frank, so it's likely that the "Sunny" writers have injected more of DeVito's personality into the character over time. While I doubt DeVito uses a toe knife as a grooming instrument, he does take pictures of his "trollfoot" and post them all over Twitter, for example! 

Each of the members of the gang have been influenced by their performers to some degree — like Dennis fasting and fainting to poke fun at Howerton's Hollywood diets, or "Green Man" being based on a friend of McElhenney's – but the jar of teeth is a DeVito deep-cut that's now part of the show canon, and that rules. 

New episodes of "It's Always Sunny in Philadelphia" premiere Wednesdays on FXX and the next day streaming on Hulu.