Well, my idea is for the future, as in it could hold within in all the available classifications for creatures. Not sure how this will go, but, here it is. This relies on the variation of color-coordination.
2 main classes:
Biotic | Abiotic
Classes in Biotic:
Single-celled, Multicellular, Small, Medium, Large, Huge.
Classes in Abiotic:
Atomic, Molecular, Small, Medium, Large, Huge.
Within each of the 5 stages of Biotic:
Bipedal
Multipedal
Limbless
Within Bipedal:
Humanoid
Divinity class
Beast
Within Multipedal:
Insectoid
Beast
Within Limbless:
Stationary
Free-floating
Shape Modification
Beast
To expand on Beast:
Those with fangs, claws, and/or brainpower not obviously within a class of a fully aware sentient being.
Within each of the 5 stages of Abiotic:
Bipedal
Multipedal
Limbless
Within Bipedal:
Construct (meaning all the possible mechanical varied creatures possible to be artificially crafted)
Natural (meaning all the possible variations of a non-living structure created by forces of nature, and are possibly embodiments of that specific element)
Within Multipedal:
Construct
Natural
Within Limbless:
Construct
Natural
Within all of the listed creatures and such, there are the effects they place on the areas around them.
Environmental:
Creatures that affect areas of the field or rely on certain permanent cards
Creature that are solitarily based
Creature that focuses on defense
Creature that focuses on offense
Creature that protects the owner
Creature that harms the owner
Creature that benefits others
Creature that manipulates the opponent's environment (directly and indirectly)
Creature that manipulates energy (quanta)
Creature that manipulates mass (immaterials)
Creature that manipulates normal game conditions (entropic forces/Quantum pillars)
I hope I covered all factors.
When classifying a creature, you move down the list, going by color. Living/Nonliving; Size; Mobility; Shape; Ability Classification.
For example: Golden Dragon is a Biotic Large Bipedal Beast Creature that focuses on offense.