In Danish folklore, the three-legged appearance of ghost horses called helhests was attributed to their sacrifice during these events. For 10 points each:
[10e] Name this type of event during which Baldr's horse and mourning wife are thrown onto his burning ship in the Prose Edda.
ANSWER: funerals [or burials]
[10m] According to Adam of Bremen, horses were among the animals hung from a tree at this Swedish city's temple every nine years in honor of Odin. King Eadgils died riding his horse in this city during one of its annual Dísablót rituals.
ANSWER: Uppsala [or Gamla Uppsala]
[10h] In Egil's saga, Egil uses a dead horse to make a nithing pole after a king's bard tries to kill him in this manner. In the Völsunga saga, Sigmund's wife kills his son Sinfjötli in this manner, after which Odin mysteriously rows away with the body.
ANSWER: poisoning their drink
<Sean Farrell , Mythology - Norse>