You have a base walking speed of 30 feet.

Due to some quirk in the biology of thirens, they have developed some resistance to effects that wear one down or corrupt. When making a saving throw against effects caused by the environment, such as regional effects or environmental conditions, add 1d8 to your roll.

You have proficiency in the Wisdom (Perception) skill

When creating a beast thiren character, choose one of the following:

Ursine thiren

Summary: Ursine thirens greatly resemble bears, with brown and black bear thirens being the most common. They tend to stretch the definition of 'medium'.
Traits:
Ability Score Increase. Your constitution Score increases by 2 and your Strength score increases by 1.
Ursine Build. You count as one size larger when determining the weight you can push, drag or lift.
Agile climber. Your base climbing speed increases by 5 feet.
Rend. You have powerful natural weaponry. Your unarmed strikes deal 1d6 slashing damage.

Lupine thiren

Summary: Lupine thirens greatly resemble wolves, with their belly fur usually being a lighter shade than the rest of their fur, which have the same colour as their natural hair colour. They tend to be in shades of grey, though there are likely wolf thirens that are more red or sandy in colour. They tend to get agitated when the moon is full, or almost full.
Traits:
Ability Score Increase. Your Dexterity score increases by 2 and your Constitution score increases by 1.
Agile. Your base walking speed increases by 5 feet.
Pack Tactics. You have advantage on attack rolls against a creature if at least one of your allies is within 5 feet of the creature and isn't incapacitated.
Rend. You have powerful natural weaponry. Your unarmed strikes deal 1d6 slashing damage.

Panther thiren

Summary: Panther thirens greatly resemble big cats like jaguars or leopards. They tend to favour ambush tactics.
Traits:
Ability Score Increase. Your Wisdom score increases by 2 and your Dexterity score increases by 1.
Ambush. If you move at least 20 feet prior to making a melee attack roll, your target is knocked prone on a hit if its size is equal to or smaller than your own.
Cat claws. You possess sharpened, retractable claws that can leave nasty scratch wounds. Unarmed strikes with your claws deal 1d6 slashing damage. Additionally, when climbing up a surface, your climbing speed is equal to your walking speed, though this does not apply to your climbing speed going down.

Pongo thiren

Summary: Pongo thirens greatly resemble great apes such as gorillas or orangutans. They are comparable in size to ursine thirens.
Traits:
Ability Score Increase. Your constitution Score increases by 2 and your Strength score increases by 1.
Long limbs. Your melee attack reach is increased by 5 feet.
Agile climber. Your base climbing speed increases by 5 feet.
Slam. You have solid natural weaponry. Your unarmed strikes deal 1d6 bludgeoning damage.

Boar thiren

Summary: Boar thirens have porcine tusks and red skin. Most of them reside in the Outer Ring.
Traits:
Ability Score Increase. Your Strength score increases by 2 and your Intelligence score increases by 1.
Charger. If you move at least 20 feet prior to making a melee attack roll, your target is pushed 10 feet away from you on a hit if its size is equal to or smaller than your own.
Gore. Your tusks are effective melee weapons in a pinch. Unarmed attacks made with your tusks deal 1d6 bludgeoning damage.

Leporine thiren

Summary: Leporine thirens resemble anthropomorphic rabbits or hares, with short, fluffy tails and large ears. Their kicks pack a punch.
Traits:
Ability Score Increase. Your Wisdom score increases by 2 and your Strength score increases by 1.
Flighty. You can dash as a bonus action.
Kick. Your legs can deliver powerful kicks. Unarmed strikes with your legs deal 1d6 bludgeoning damage.