Fasnacht Day

Fasnacht Day is an event quest first introduced in the Fallout 76 Wild Appalachia update. The quest was first available from March 19-26, 2019. It returned on May 27, 2020, and will run until June 9.

Detailed walkthrough
To start the event, speak to the Master of Ceremonies in Helvetia at the top of the real-life hour (at XX:00). Once started, the residents involved in the event must find five of the randomly-assigned protectron marchers in the town. Each protectron will provide a task corresponding to their profession, and each task must be completed before the parade can begin. After a task is finished, the relevant marcher will walk to the center of town, equip its Fasnacht mask, and wait for the others to arrive. The possible protectrons and corresponding tasks are as follows:
 * Cheerful Beekeeper: Exterminate the honey beasts which are attacking the Honey Haus.
 * Happy Candlemaker: Donate beeswax from the Honey Haus hives to the Candlemaker (0/10)
 * Gleeful Butcher: Donate intestines from animals at the Butcher's Cooler (0/12)
 * Jolly Baker: Donate radtoad eggs from the stream to the Pantry (0/20)
 * Convivial Historian: Bring old Fasnacht steins to the museum for analysis (0/12)
 * Joyous Musician: Play some music onstage.
 * Jubilant Decorator: Decorate the barn.
 * Merry Woodsman: Add wood to the bonfire (0/50)

Once all five tasks are completed and all five protectrons assemble in the center of town, the Master of Ceremonies rushes over to join them and take point as parade leader, and the parade begins its route. First, the group walks east down Pickens Rd. to the front of Freyja's Haus, the yellow-painted restaurant, where it is attacked by swarms of radtoads. After the creatures are eliminated, the group moves north over the wooden bridge toward the Cheese Haus. The marchers stop in the middle of the field as super mutants and super mutant suiciders charge the group. Once the mutant assault has stopped, the marchers continue south. Finally, when the parade stops in front of the chapel, hordes of stingwings and wolves attack. A legendary megasloth also spawns near the post office. The enemies spawn and attack when the music played by the Master of Ceremonies abruptly slows and stops before recovering, then repeats once the attack is over and the parade resumes.

After the enemies have been killed, the Fasnacht bonfire must be lit. At least one protectron marcher needs to be kept alive in order to complete the event, with more survivors netting greater rewards. The participants will also be granted a random legendary weapon or armor piece.

Masks
These are the available Fasnacht masks and hats:

Introduced in 2020

 * Fasnacht crazy guy mask
 * Fasnacht deathclaw mask
 * Fasnacht Father Winter helmet
 * Fasnacht raven mask

Atomic Shop

 * Fasnacht blue crazy guy mask
 * Fasnacht green crazy guy mask
 * Fasnacht Moonshine Mama mask
 * Fasnacht Old Man Summer mask

Behind the scenes

 * Fastnacht is an actual annual carnival celebrated by German and Swiss people while traditionally wearing masks that represent demons, jesters, witches and animals. In Helvetia, West Virginia it is normally celebrated once per year on the first weekend after Fat Tuesday, and concludes with the burning of an effigy in a bonfire, without any robots or megasloths.
 * The music played during the Fasnacht parade is the 2004 One More Pils instrumental exercise composed by Andy Vale and licensed from APM Music. While the original piece is 1:10 minutes long, the version used in-game is comprised of two 15 second clips that endlessly repeat one after another.