Critical Gas is the first part of the 25th episode in the second season of Dexter's Laboratory, which first aired on February 4, 1998. In this episode, Dexter eats a huge burrito from Burrito Palace, and has a bad case of abdominal pain. Thinking that he's going to pass away, Dexter does all of the things he can before time runs out.
Dexter takes a lunch break, ordering a 'Big Bad Burrito' from Burrito Palace. After eating the burrito, he experiences terrible pain in his stomach. Computer explains there is a gaseous formation growing inside of him at an "alarmingly high" rate. After experimentation with a balloon and a bicycle pump, it pops and Dexter believes he is going to die. He then makes a list of things to do before he dies, and sets out to complete it within thirty minutes. First, he first wears his bunny pajamas for Mom. Next, he adds a bowling lane in the livingroom for Dad, who calls it "The greatest gift that has ever been given in the history of gift giving." Then, he tells his robots that they are free. They fail to understand, so Dexter orders them to "Go out there and be free." They leave the lab, still confused, and Dexter tells them to "Figure it out." Just as they begin to understand that they are free, they are run over by a truck. He then creates world peace, ends world hunger, learns to dance, washes the dishes, proves existence of life on other planets, and does the laundry. The next item on his list is to "Be nice to Dee Dee" which he completes by giving her the lab. As Dee Dee begins destroying the lab in joy, Dexter tells Computer that due to certain complications, he will be performing a permanent total system shut down. Computer asks what will happen to her, and Dexter says he doesn't know. Computer says she understands, and Dexter apologizes as he pushes the shutdown button. With two minutes remaining, the final item on his list is to tell his parents about his secret laboratory. Dexter enters the livingroom, turning off the movie that Mom and Dad are watching. He apologizes for his rudeness, and explains that he has something "very important" to tell them. They assure him that he can talk to them about anything, and just as he is about to tell them, he falls to his knees in pain. He farts, with enough force to blow the TV behind him into the wall, and apparently enough volume to be heard outside of the Milky Way. His parents are shocked, and Dexter is horribly embarassed, but glad that he isn't going to die. The episode Irises out stopping at Dexter's back, and continuing as the screen begins shaking with the sound of him farting again.
Dexter: (watch beeps) Oh, lunch time! (answers phone) Yes, hello, Burrito Palace? I would like to order a Big Bad Burrito, please. Thank you, goodbye.
Dexter: Ohh, the mother of all Burritos.
Mom: Oh, your bunny pajamas! I thought you hated those.
Dad: Son, you have given me the greatest gift that has ever been given in the history of gift giving!
Dexter: You stupid robots! I order you to go out there and be free!
The title of the episode is an allusion to "Critical Mass" which is the smallest amount of fissile material needed for a sustained nuclear reaction.
Second time the President of the USA is mentioned and the first time he is physically seen. First time was in "The Big Sister" and the third time was in "Let's Save the World You Jerk!". Like in "The Big Sister", the President is a parody of Bill Clinton.