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