(Going counterclockwise starting from the centre top) Freyr and his boar Gullinbursti being defeated by the fire giant Surtr. Either Hari or Skoll devouring the sun. Thor fighting Jörmungandr the world serpent. Valkyries fighting off various giants. Heimdall sounding Gjallarhorn to herald the beginning of Ragnarök. Týr (who lost his arm to Fenrir when trying to bind him in chains) fighting Garmr. Hel (the half white and half red figure below Freyr) and the armies of Hel slaughtering the remaining humans. Loki and Heimdall killing each other. Líf and Lífþrasir, two humans fated to survive Ragnarök and will repopulate the earth afterwards (basically Norse Adam and Eve). Odin riding his eight-legged steed Sleipnir against Fenrir (fun fact, Sleipnir was born after Loki turned into a female horse to lure a giants steed away so the Gods could get out of paying a giant for building a wall) Loki riding Naglfar, the ship of nails (not metal carpentry nails, it's made of human fingernails and toenails). Either Hari or Skoll devouring the moon. Norse mythology is fascinating. EDIT: Seems I overlooked Víðarr (Odins son who'll kill Fenrir to avenge his father) slashing Fenrirs mouth.