Schleibeldorg

Schleibeldorg is the mourning ritual carried out by Ruffnut Thorston in "Snuffnut" when she believed her brother Tuffnut Thorston had died.

History
Not much is known of the ritual, but when Ruff mentioned she'd be carrying it out, Astrid questions the term, sounding to not recognize it. It's possible only the Thorston family observes it when a loved one dies.

Practices
According to Ruff, it's customary to lock oneself in the dark for two days in observance of Schlebeldorg, and eat nothing but Sea Slugs and toe nails during that time. She's later also heard yelling in her hut and throwing objects around, likely breaking many of them and making a huge mess, though it is uncertain if this is part of the ritual.

Mentions
Both Ruffnut and Astrid mention it in the Dragons: Race to the Edge, Season 5 episode "Snuffnut".

Trivia

 * The word "Schlebeldorg" doesn't exist, but the prefix schlebe in Germanic roughly translates to "segment", or "cut off", which would make sense given the mourner is to cut themselves off from society for two days.