Christine Baranski recorded a song "Bringing Happy Back" to come just after Chef proclaims "I am that he." It was decided that it made Chef a too sympathetic character, as it seems like she genuinely wants to restore happiness to Bergen town, so it was cut. It can be heard on the Blu-ray extras with storyboard drawings.
The original troll doll was created by Thomas Dam from Gjøl in Denmark in 1958. The first ones were filled with wood shavings. Many styles and sizes were made and even animals from donkeys, elephants, giraffes, horses, lions and monkeys. There is even a story about why they are different sizes.
When Princess Poppy is dancing in the large basket costume and gloves, it's a hat-tip to the "bring it on down" characters Justin Timberlake has portrayed on Saturday Night Live (1975).
When Poppy and Branch first enter the Bergen castle, they briefly pass by a painting that parodies the famous Norman Rockwell painting "Freedom from Want" which shows a family around the table for Thanksgiving dinner. In this version, it depicts Bergens around the table for the Trollstice feast.
At the beginning of the movie, a remix of the classical piece "In the Hall of the Mountain King" by Edvard Grieg is playing, while the camera travels through the hall of the Bergen king's castle, which is on top of a mountain. Bergen is also the name of Grieg's hometown, one of the larger cities in Norway. Moreover, the city name Bergen is related to the word "Berg" which simply means "mountain" in several Germanic languages, including German, Dutch, Swedish and Norwegian.