Terms of the non-human community you should probably know:
Otherkin (Otherkinity) - Someone who either spiritually or psychologically identifies as non-human.
Therian (Therianthrope) - Someone who spiritually or psychologically identifies as an animal that exists or existed on earth.
Theriomythic - Essentially the same as Otherkin, but identifies as a feral/uncivilized creature from myth, and is animalistic in nature.
Fictionkin (AKA Otakukin) - Someone who either spiritually or mentally identifies as a fictional character or of a creature from a fictional series.
Draconic (Draconity) - Someone who spiritually or mentally identifies as a dragon.
Animafidem (Animafidemism) - Someone who spiritually identifies as non-human, because they believe their soul is non-human.
Cerebrumalius (Cerebrumalia) - Someone who psychologically identifies as non-human, because they believe their brain responsible.
Incarnate (Reincarnation) - Someone who believes they are an incarnation of someone/something from a past life.
Otherhearted - Someone who strongly identifies with something non-human.
Copinglink - Someone who creates or has an identity to cope with mental illness. Not the same as an otherkin or therian.
Kintype - The type of being an otherkin identifies as.
Theriotype - The type of animal a therian identifies as.
Spirit Guide - A spirit of any species that guides you along your path. A seperate entity from your being.
Awakening - When you realize that you identify as something other than human and discover what you are on the inside. “Awakening your otherself”
Astral Limbs - The sensation of limbs that you do not possess in this life, that one believes exist on the astral.
Supernumerary Phantom Limbs - The sensation of limbs you do not posses in this life.
Phantom Limbs - The sensation of a limb or limbs someone used to have, but have lost or were amputated. (Not the same as supernumerary limbs and not non-human)
Astral-Shift - (A-shift) Spiritually shifting into that which you identify in the astral realm. Although it is believed one can take any form there.
Mental-Shift - (M-shift) Mentally shifting into the mentality, instincts, and urges of that which you identify.
Aura-shift - When someone’s aura field takes the shape of that which they identify.
Cameo-shift - A temporary shift into something that doesn’t last and isn’t actually you. Often confused with an actual shift.
P-Shift (Physical Shift) - Turning into that which you identify physically, which under any circumstance is not physically possible. This does not and can not happen. Any claims of this are liars, scammers, or under delusional impression.
Greymuzzle - An older member of the community, usually having been a member for at least 10 years, or are someone highly respected.
Fledgling - Newer members of the community, usually for no longer than 1 year.
Polykin - An otherkin with multiple kintypes, or having more than one thing that they identify as.
Polytherian - A therian with multiple theriotypes, or having more than one thing that they identify as.
Cladotherian - A therian who believes they do not just fit one specific species, but the whole species or “clade” of that type. (Ex. Not just a housecat, but all species of cat)