Here is the full list of all 39 Vikings - there are Wolves of Midgard achievements.
Equip three runes on a single item.
Found all Legendary Items.
Unlock all Gifts in Skathi's gift tree.
Unlock all Gifts in Tyr's gift tree.
Unlock all Gifts in Odin's gift tree.
Unlock all Gifts in Thor's gift tree.
Complete the game as the Shieldmaiden.
Complete the game on the highest difficulty.
Complete Campaign 3.
Accomplish campaign in Valhalla Mode
Accomplish campaign in Valhalla Mode on highest difficulty.
Complete all Challenges on all maps.
Earn 50,000 gold by selling resources.
Unlock level 4 of the Shipmaster.
Complete any Hunt map.
Complete the Imp Hunt.
Complete all Trials.
Rage continuously for over 20 seconds.
Kill 100 Jotun.
Unlock level 5 of the Smithy.
Kill four foes in a single attack.
Earn 1,000,000 Blood.
Killed 500 Tomte.
Become chieftain of all the clans.
Complete Campaign 2.
Burn the Imperial Fleet.
Unlock all Gifts in Loki's gift tree.
Perform 1000 rolls.
Liberate Flotnar village.
Complete Campaign 1.
Travel to Utgard.
Survive the Mire-Witch's spell.
Defeat the Jokul.
Defend Ulfung Village.
Complete the game as the Warrior.
Complete Game+.
Keep Draupnir for yourself.
All Hunt maps complete.
Collect one of every rune.