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