Here is the full list of all 24 Beast Quest achievements.
Complete all other achievements.
Complete the game in Beast Master difficulty mode.
Free the four Beasts of Avantia.
Unlock all upgrades in the Skill Tree.
Call on each of the Allies in battle.
Complete all of the side-quests in Avantia.
Free Ferno the Fire Dragon from Malvel's curse.
Free Nanook the Snow Monster from Malvel's curse.
Free Arcta the Mountain Giant from Malvel's curse.
Hunt all of the Shadow Marks.
Hunt one of Avantia's Shadow Marks.
Help the Beastologist to find her masterpieces.
Help Zoltan the Pet Rock to see the sights.
Help the Baker to make a batch of Sword Cookies.
Defeat 500 enemies in total.
Collect all of the items that Ekalb needs to prove his magic.
Unlock 10 Gold Chests.
Unlock 10 Iron Chests.
Unlock 10 Bronze Chests.
Meet Silver and have him join your Beast Quest.
Meet Elenna and have her join your Beast Quest.
Get 50 Perfect Dodge bonuses in combat.
Get 50 Multi-KO bonuses in combat.
Get 50 Flawless bonuses in combat.