Monks of the way of the beasts embody the Ki energy of certain animals of the wild. They adapt behaviors of the animals to enhance their effectiveness.

Beast Stance

3rd-level Way of the Beast feature

Starting when you choose this tradition at 3rd level, you can embody the Ki of animals as your own.
As a Bonus Action, you can spend 1 Ki point to enter into or change your Beast Stance. You can stay in your stance for a total of 1 minute, after which you can spend another Ki point to keep the stance going. The stances available to you are:

Cheetah:
You ignore difficult terrain and you can take the pounce action.
Pounce: On a successful hit, against a target you spent 20ft moving to, you can force the target to make a Strength saving throw or be knocked prone.

Monkey:
You gain a climbing speed equal to your walking speed. In addition, all monk weapons have the thrown (20/60) property.

Snake:
You can now spend a Bonus action to try and break out of grapple. Additionally, you can now make Acrobatics(Dex) checks instead of Athletics(Str) checks to grapple a target.

 

Beast Sense

6th-level Way of the Beast feature

At 6th level, your animal instincts further refine. You can spend 2 Ki points to cast either Speak with Animals, Beast Sense, Animal Friendship, or Animal Messenger.

 

Beastial Improvement

11th-level Way of the Beast feature

At 11th level, you hone your stances as well as learn new stances. You can now spend an additional Ki point to go into a secondary stance while in your first one. This lasts until the end of your next turn and at the end you can decide which stance you want to continue in.
Stances:

Cheetah:
Whenever you use your Flurry of Blows, you can spend 2 Ki points instead of 1 to make three unarmed strikes.

Monkey:
You can spend 2 Ki points to use Deflect Missiles on a melee attack. If the damage is reduced to 0 due to this, you disarm the target. Additionally, you gain advantage on Dexterity Saving Throws.

Snake:
You can spend 2 Ki points to deal an extra 1d4 poison damage on an unarmed strike. In addition, you score a critical hit on a roll of 19-20.

Ape:
You gain 10 temporary hit points and have advantage on Strength based checks.

Mantis:
Your unarmed strikes have the Reach property.

Beast Master

17th-level Way of the Beast feature

Beginning at level 17th, you master your stances and you learn some rare stances.
You no longer need a bonus action to change your stance. Additionally, You can stay in a stance for up to 10 minutes now. To enter into one of the rare stances you must spend 2 Ki points, no matter if you are entering into or changing to.

Cheetah:
Your pounce now does 2d8 bludgeoning damage.

Snake:
Your unarmed strikes now do 4d4 poison damage.

Lizard:
You can spend 10 minutes to completely shed your skin and create an almost perfect copy of yourself. It Follows your behavioral patterns, but can not think for itself. You can communicate with it telepathically, as long as it is within a 100ft, and it has half as many hit points as you.

Owl:
You gain True sight for 60ft and advantage on Wisdom ability checks.

Turtle:
You gain resistance to piercing, slashing, and bludgeoning damage. Additionally, you can spend 1 Ki point to gain resistance to fire, cold, lightning, poison, and thunder damage until the start of your next turn.