academy, magical totem animals

An academy hidden deep in a magical forest, but anyone can get in. The academy has tiers, with stronger students at higher tiers and the weakest at the lowest tier—tier 1. Strength here isn't measured in magic, but in totem creatures. On their 16th birthday, a person (who doesn't even have to be an academy member) will receive their totem animal. So why specifically animals? The larger the animal, the more loyal it will be to the person, and if it obeys, it means the person is strong. After all, leviathans, even ordinary wolves, obey only those they choose and who can resist them. Otherwise, animals are random. Until age 16, the academy tiers aren't based on familiars or totem animals, but on the strength of the student. Good luck if you can survive in such a complex world.