Regular animals, which can also be called rare animals (despite some being fairly common) are animals which are not the base animal, or the normal species of that animal, but can only be found in the stampede through normal play. There have been five regular animals that have been released separately from the rest of their species, four for the Halloween event and one simply being released as an add-on after Rodeo Stampede asked players on social media to share a certain image a certain amount of times to be rewarded with new animals to find. All regular animals give animal mastery XP.
In the Space Zoo, regular animals are unlocked progressively as the player upgrades their habitat, which differs from the Sky Zoo, where all regular animals are already unlocked once the base animal has been tamed.