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