Trollstice was a holiday the Bergens in Bergen Town had. After discovering the Trolls and feeling happy after eating them, the bergen caged the Troll Tree and created a tradition where once a year, they would gather around the Troll tree and each would get a feeling of happiness by eating a Troll.
During a Trollstice where Prince Gristle was supposed to eat Princess Poppy, the Trolls (led by king Peppy) escaped and as a result, the Bergens were unable to celebrate the holiday for 20 years.
When Chef captured the Trolls, the Bergens were going to celebrate Trollstice again and Chef wanted to make it so that the Bergens could celebrate Trollstice everyday but After Poppy and her friends The Snack Pack showed the bergen how to be truly happy, Prince Gristle abolished Tollstice.
Trollstice is Febuary 19th.