Background: Kermit the Frog is a Muppet character and Jim Henson's most well-known creation. Introduced in 1955, Kermit serves as the straight man protagonist of numerous Muppet productions, most notably Sesame Street and The Muppet Show, as well as in other television series, films, specials, and public service announcements through the years. Henson originally performed Kermit until his death in 1990; Steve Whitmire performed Kermit from that time up until his dismissal from the role in 2016.
Context: A biography has been developed for Kermit the Frog as if he was an actual living performer rather than a puppet character. According to this fictional biography, he was born in Leland, Mississippi alongside approximately 2,353 siblings, though a 2011 "interview" on The Ellen DeGeneres Show has him state that he was from the swamps of Louisiana. As portrayed in the 2002 film Kermit's Swamp Years, at the age of 12, he was the first of his siblings to leave the swamp, and one of the first frogs to talk to humans. He is shown in the film encountering a 12-year-old Jim Henson (played by Christian Kriebel) for the first time. According to The Muppet Movie, Kermit returned to the swamp, where a passing agent (Dom DeLuise) noted he had talent and, thus inspired, he headed to Hollywood, encountering the rest of the Muppets along the way. Together, they were given a standard "rich and famous" contract by Lew Lord (Orson Welles) of Wide World Studios and began their showbiz careers. In Before You Leap, Kermit again references encountering Jim Henson sometime after the events depicted in the course of The Muppet Movie and details their friendship and their partnership in the entertainment industry, crediting Henson as being the individual to whom he owes his fame. At some point after the events of The Muppet Movie, Kermit and the other Muppets begin The Muppet Show, and the characters remain together as a group, before starring in the other Muppet films and Muppets Tonight, with Kermit usually at the core of the stories as the lead protagonist. Kermit is shown in The Muppet Movie as stating that the events of the film are "approximate to how it happened" when asked by his nephew Robin about how the Muppets got started. Fozzie Bear is portrayed as Kermit's best friend--a fact reiterated by Kermit in Before You Leap--and the two were frequently seen together during sketches on The Muppet Show and in other Muppet-related media and merchandise. On August 4, 2015, Kermit the Frog and Miss Piggy "announced" that they had ended their romantic relationship. On September 2, 2015, Kermit was stated to have found a new girlfriend, a pig named Denise, but around February 2016, Denise supposedly broke up with Kermit after almost six months together.
Question: What is the first movie they made?

Answer:
The Muppet Movie