When determining your character’s ability scores, increase one score by 2 and increase a different score by 1, or increase three different scores by 1.

Although Kitsune reach physical maturity at about the same age as humans, Kitsune live for an unknown amount of time and do not physically age after reaching maturity. When a kitsune reaches the age of 1,000, it becomes a powerful tenko, an extremely rare occurrence. You are an adult kitsune, at least 200 years old.

When in fox form, you are size Small. When in humanoid form, you are size Medium.

When in fox form, you have a walking speed of equal to 10 + (10 x number of your tails) feet, and a burrowing speed of 10ft. (Ex. 3 tailed kitsune has 40ft movement speed)

When in humanoid form, you have a walking speed of equal to 20 + (5 x number of your tails) feet. (Ex. 3 tailed kitsune has 35ft movement speed)

When in fox form, you can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray. When in humanoid form this range decreases to 30 feet.

A kitsune is born with only one tail, but every 100 years a kitsune will grow an additional tail until they reach nine tails. In extremely rare occurrences a significant event can cause a kitsune to grow an additional tail, such as gaining a great amount of power or a god granting them one. You are an adult and have at least three tails.

These tails grant you power. You gain a bonus to your AC equal to 1 + 1/3 number of tails rounded down if you are not wearing armor. You also gain a bonus to saving throws equal to 1 + 1/3 number of tails rounded down. 

Due to the tricky nature of kitsune, you have proficiency in the Deception skill.

You can speak, read, and write Common and one other language of your choice.

A kitsune may take on human form, an ability learned when it reaches a certain age—usually 100 years, though particularly clever or skilled ones can learn in as early as 50. An experienced kitsune has no limit to what gender or age they can shapeshift into. Less experienced kitsune usually stick to one human form until they grow older and gain more control over their powers.

As an action, you can shift between your fox and human forms. You can also keep your tails and fox ears in your human form if you wish and take the form of a kemonomimi. 

Your human form is medium-sized and has a walking speed of equal to 20 + (5 x number of your tails) feet. Your fox form is small-sized, has a walking speed of equal to 10 + (10 x number of your tails) feet, and a burrowing speed of 10 feet. 

In your fox form, you have the same health, AC, ability stats, saving throws, and skills as your human form. However, you are restricted by the physical limitations of your fox form, such as having no hands and not being able to speak, so skills like sleight of hand or persuasion might be impacted negatively. The specific limitations of your fox form are up to you and the DM. 

If you are killed in either of these forms you will revert back to your natural fox form after death. 

In your fox form, you have the keen senses and agility of a fox, you gain advantage on perception checks based on scent or sound, acrobatics checks, and dexterity saving throws. 

You cannot cast spells in your fox form until you reach 7th level. Shifting to your fox form doesn’t break your concentration on a spell you’ve already cast. Any equipment you have can be merged into your fox form when you shift, but you do not gain their effects and you cannot access them until you change into your human form. You can choose to keep any part of your equipment unmerged, but it does not change its size. So you could keep something small like your component pouch on you, but items like your armor will not fit you. You can also choose to wear armor or items fitted for your fox form. In that case, that equipment will merge with you when you turn human and you will only gain their effects while in fox form. 

In your fox form, you may make a bite attack that does piercing damage depending on your level and number of tails + your dex modifier. Your tail count determines the type of die and your level determines how many die. 

If you have at least 2 tails it is a d4. At least 4 tails is a d6. At least 6 tails is a d8. At least 8 tails is a d10. And 9 tails is a d12. At 1st level it's 1 die. At 5th level it's 2 dice. At 10th level it's 3 dice. At 15th level it's 4 dice. At 20th level it's 5 dice.
(Ex. a lvl 10 kitsune with 5 tails would do 3d6 + dex mod damage)

As an action, you can summon foxfire in your fox or human form. Foxfire presents as a glowing orb of (usually blue) fire that circles around your head. One orb is 10 feet bright light and 10 feet dim light. How many orbs you have determines how much light is shed. Every additional orb lit adds 5 feet to the bright light and 5 feet to the dim.
Your level determines how many orbs you have and your number of tails determines their strength.
At level 1, you start out with 1 orb. When you reach 5th level, you create three orbs. At 10th level, you create five orbs. At 15th level, you create seven orbs. At 20th level, you create nine orbs.
If you have 3-6 tails, they do a d8 of fire damage, if you have 7-8 tails they do a d10 of damage, if you have 9 tails they do a d12 of damage.
Throwing the foxfire orbs takes a bonus action, you may only throw as many orbs in one turn as half the number of tails you have, rounded up (Ex. a 5 tailed fox can do 3d8 damage in one turn). You can choose to use Charisma, Intelligence, or Wisdom as your spellcasting ability for this attack. The orbs have a range equal to your number of tails x 10ft. Once all of the orbs are gone, the effect ends.

Kistune can imitate the form of another person, but getting down a person's accurate likeness is very difficult for kitsune who are not experienced.

Starting at 5th level you have started to gain experience in your shapeshifting skills, if you spend at least 9 minutes studying a person, as an action you can shift into their image perfectly for a number of hours equal to one-fifthof your level rounded down. Anyone attempting to detect your true nature may attempt a Wisdom (Insight) check contested by your Charisma (Deception). The accuracy of your transformation is affected by how well you studied your subject. For example, if you did not hear your target speak then you cannot imitate their voice. 
You can use this ability a number of times equal to your tails per long rest. 

Very experienced kitsune can easily take the forms of other humanoid races.
Starting at 11th level,  you gain mastery over your shapeshifting abilities and can now shift into any humanoid race as your human form, but you do not gain any of their racial traits.

Starting at 7th level, you can cast spells with only somatic and material requirements in your fox form, using your tails to help you. Additionally, you can cast spells that require verbal components at levels equal to or lower than number of tails you have, but you can only cast a cantrip this way if it does not do damage. (Ex. 3 tails = only lvl 3 and under spells)

Staring at 13th level, you can now benefit from the effects of any item that you have attuned to that does not have to be held.

Starting at 17th level, you have reached new heights of power and control. You no longer need to speak to cast spells in your fox form and can now cast spells with verbal requirements.