Your Constitution increases by 1, and one other ability score of your choice increases by 2

Aliens come from many places and come in all different forms. Your age can be your own choice or your Dungeon Master's, possibly ranging anywhere from a decade to thousands of years. 

Aliens are often chaotic as they don't necessarily conform with the various laws of different lands

Aliens can be anywhere from 2 to 8 feet tall. If you choose to be 2 to 4 feet tall, your size is small. Otherwise your size is medium.

Your base walking speed is 30 feet.

Your alienated origins cause you to have a very different build to others. At 1st level, you choose one of the following features, and can choose a second at 4th level:

Webbed and gilled. Your hands and feet are webbed to give you a swimming speed of 35 feet. Furthermore, you have gills on your neck that allow you to breathe under water.  If you take this feature you cannot choose the Inversed legs feature later.

Inversed legs. Your legs are built much like that of a wolf or kangaroo, and allow you to move very quickly on land. While moving on land, your base speed increases by 10 feet. This speed bonus does not carry over to climbing speed or swimming speed. If you take this feature you cannot choose the Webbed and Gilled feature later.

Extra limbs. An extra pair of arms are stationed on your shoulders, giving you a total of 4 arms. You can use these arms to manipulate objects and do anything your normal arms can do, except to make attacks. Your extra limbs can make it hard to wear traditional armour, and may need to be modified to be worn.

Maximised eyesight. You gain 300 feet of Darkvision

Tail. You have a spined tail that you can use to make attacks. Instead of the traditional unarmed strike, you can use your tail to make an attack. You can use either your Dexterity or Strength modifier for this attack. The attack deals piercing damage equal to 1d12+ Your strength or Dexterity modifier. 

Environmental Resistance. You are suited to a specific type of environment, and gain one damage resistance of your choice.

Wings. You have large wings that can fold seamlessly onto your back. These wings can be reptilian, feathered, bugged or anything else. You gain a flying speed of 25 feet while not wearing heavy armour

You can speak Common, although you cannot read or write it. Additionally, you know an exotic language known only by your own species which you can speak, read and write. You also know how to speak one other language of your choice.