Genus is meant to be a broad classification of the type of creature -- from a taxonomy point of view, the reference to genus here would be a combination of both "genus" and "family" in a taxonomy classification structure.
Some minis might have 2 or more genus tags that would apply to them, such as:
Dragons: dragons have 2 genus tags associated with them: dragon and the dragon type (chromatic dragon, metallic dragon, gem dragon, or shadow dragon).
Some commonly overlooked tags are:
- anthropomorphic - used for any humanoid with animal characteristics. Most lycanthropes would also have this tag.
- avian - used for any type of bird-family related creatures and humanoids, including aarakocra and kenku.
- canine - used for any "canis" animal, including dogs and wolves.
- draconic - used for any non-dragon humanoid mini which has draconic features, including dragonborn and kobolds.
- feline - used for any type of cat-family related creature and humanoids, including tabaxi.
- goblinoid - used for any type of goblin-related creature, including goblins, hobgoblins, and bugbears.
- hyaena - used for any type of hyena-related creature, including gnolls.
- piscine - used for any type of fish-related creature and humanoids, including sahuagin.
- reptilian - used for any type of reptilian-family related creatures and humanoids, including lizardfolk and troglodytes.
- tauric - used for any type of mini related to bulls, such as minotaur.
- ursine - used for any type of bear-related creature.