you can use your action to grapple a target.

When using your tail to grapple you have advantage on contested strength(athletics) checks when grappling a target including when the target attempts to escape.

While the target is grappled, you can use your bonus action to tighten your grasp, if the target fails a strength saving throw with a DC of 8+ proficiency bonus+your strength modifier they take 1d4+str bludgeoning damage, if the target succeeds they take half of that damage. The damage from this feature increases at 4th level; 1d8, 8th level; 1d12, 12th level; 2d8.

While your target is  grappled you can add your proficiency bonus onto any intimidation rolls even if you where already proficient. at level 3, Once between short or long rests, as an action you can use this freature to make a charisma(intimidation) check ,if the roll is below 13 the effect automatically fails, however if you roll over 13 the target creature must make a wisdom saving throw, if the creature fails they are frightened of you, each round the target gets to make a DC10 wisdom save to attempt to shake off the frightened effect, this effect can last for up to 1 minute.

You are proficient in the stealth skill

You can see 60 feet non-magical darkness.

You can use the shove action from 10 feet away.

You take more damage from cold. If an attack that deals cold damage hits you, the attacker gets to roll dice equal to 1.5 times the normal dice, rounded up. For example if the attacker rolls 5d8 cold damage, they get to roll 8d8 as 1/2 of 5(the original number of dice) is 2.5, rounded up this is 3, the sum is 3+5=8.

Your strength ability score increases by 1, your constitution score increases by 2

You reach maturity at the age of 8 and tend to only live until around 60.

Although at full length you can extend over 14 feet, you are counted  as a medium size creature, this is because your tail is often curled below you. The waist upwards is the size of a normal human. Due to your larger volume you tend to weigh over 240 pounds.