As an action, you can transform your appearance or revert to your natural form. You can’t duplicate the appearance of a creature you’ve never seen, and you revert to your natural form if you die.

You decide what you look like, including your height, weight, facial features, the sound of your voice, coloration, hair length, sex, and any other distinguishing characteristics. You can make yourself appear as a member of another race, though none of your game statistics change. 

 You also can't appear as a creature of a different size than you, and your basic shape stays the same; if you’re bipedal, you can’t use this trait to become quadrupedal, for instance. Your clothing and other equipment don’t change in appearance, size, or shape to match your new form, requiring you to keep a few extra outfits on hand to make the most compelling disguise possible.

Even to the most astute observers, your ruse is usually indiscernible. If you rouse suspicion, if a wary creature suspects something is amiss, you have advantage on any Charisma (Deception) check you make to avoid detection. However your disguise does not stand up to the touch.

Your Charisma score increases by 1, and your dexterity increases by 2.

While in your true form you can stick to walls. And gain a 5 ft climbing speed.

in your true form you can fit through spaces as small as one foot in diameter. However your equipment is not amorphous.