Watch Hilarious Video Of Nick Offerman Reading 'Twas The Night Before Christmas' On 'The Tonight Show': Pius 'Parks & Rec' Star & Ansari Spoil Series Finale Lines! [VIDEO]

Do Nick Offerman and Aziz Ansari get the last lines in Parks & Recreation's series finale? And why was Offerman vomiting and crying during it? Offerman — who plays Ron Swanson in the beloved NBC sitcom — came close to spoiling the ending of Amy Poehler's small town bureaucratic comedy while chatting to Jimmy Fallon on The Tonight Show last night, while also revealing that he learned his deadpan delivery in church, and helped Jimmy out by reciting his very own literal version of 'Twas the Night Before Christmas', and the results are predictably amazing.

Promoting his new stand up special, Nick Offerman: American Ham as well as the final series of Parks & Recreation Offerman revealed to Fallon that his sense of humor came from his family, saying that because he "grew up in a farm family", everybody was "very dry". As he says, it was born out of necessity, pointing out that "When your entire year's work can be wiped out by a storm, you have to either be a smartass, or kill yourself."

"So you see the corn washing down the river and you say 'looks like we're be eating jerky'. 'I'm glad we canned those beets.'"

As for his unique deadpan delivery, Offerman says "I think I first learned it in the Catholic church, I used to do the readings."

He continues, saying "You're reading the story of Jesus, and bull-rushes, and Moses... and you'll come upon a sentence like 'And Jesus did came upon the peoples'... And if you just say that with enough gravity..." Watch what happens next below!

As for his iconic role as Ron Swanson in Parks & Recreation, Offerman says it was tears all round as they wrapped the show... but that he was also offering up more bodily explosions.

According to Offerman, Parks & Rec showrunner Mike Shur, "went around and said 'that's a series wrap on Parks and Recreation' and everyone was crying, except I was vomiting and crying," he laughs, "and filling my pants with oatmeal. It was a full catharsis."

He also revealed that he and Aziz Ansari injected themselves into the final scene of the beloved show, saying that after "on the last day" during a final crowd scene he and Ansari realized they had no more lines, so, says Offerman, "Aziz suggested that at the end of the scene Amy and Aubrey would leave and so we began to just say 'Bye guys!' So we could have a solid last contribution."

Watch Offerman explaining the scene below. Parks & Recreation's seventh and final season begins Jan. 13 on NBC.

And if you want more Offerman beyond Ron Swanson, his new stand up special, Nick Offerman: American Ham, just debuted on Netflix and is streaming now. Watch a clip from it below!