Your Constitution score increases by 2 and one other score of your choice is increased by 1.

Slime's do not age as other races do, and can theoretically live forever so long as they receive adequate nutrition. You also do not need to breathe in any form and can live in almost any environment.

In their true form Slimes range anywhere from 2 feet tall to 4 feet tall and they are Small creatures. Their girth almost always exceeds their height. It is rare for a slime to exceed even 60 pounds, with most weighing in between 20 and 40 pounds.

While in your true form your base walking speed is 20 feet and your swimming speed is 40 feet.

You are able to speak Common and Undercommon.

You have blindsight to a range of 60 feet. You are blind beyond this range.

You do not eat or drink as most creatures do, but instead receive nutrients from material dissolved within you. You can become intoxicated from ingesting alcohol but at any given time you can cleanse your body and remove the intoxication. You have advantage on saving throws against being poisoned. You do not sleep and magic cannot put you to sleep if you are not willing. Instead, you enter a torpor during which time you remain semiconscious, for 4 hours a day. After resting in this way, you gain the same benefit that a human does from 8 hours of sleep.

Like most Slimes you are always hungry, unlike most Slimes tho you can somewhat control the urge to Devour everything. You can eat almost everything as your body is able to break down almost all types of matter (This limit is set by your DM). You must Devour something every 24 hours or your body slowly starts to break down and become less viscous until you are nothing but a puddle of liquid that slowly fades away. If you do not Devour something for 3 days you die.

When you Devour something you can choose to store it inside your Inter-dimensional Pocket. You are not able to wear anything while in your natural form but any Magical Item you Devour and store inside you can be equipped and attuned just like normal races, with the exceptions to Magical Armors. If you attune to a Magical Armor you only gain the effects of the armor but NO AC.

You are able to store the appearance of a set number of creatures you Devour for your Ever Changing Fluids ability. Only creatures that are Medium or smaller can have their appearance stored for use. You are able to pick what appearances you wish you keep and remove as you learn more. You can store a number of appearances equal to your Proficiency Bonus. You are only able to store the appearances of creatures that have died within the last 24 hours. Any creatures appearance you store for use later is dissolved inside you and does provide nutrients.

Your body is made up of dense viscous liquid that seems to have absorbed some magical properties due to the experiments. Any time you Devour anything you can absorb it for nutrients and melt it down or choose store it in some Inter-dimensional Pocket in your body.  You are unsure what exact experiment created this pocket but it feels like an extension of your body, you are able to see anything inside the space and interact with anything too.

The pocket starts off really small at 1 foot in width, length and height and will increase in size as you grow stronger. The size in feet is always half of your level rounded down. So at level 20 it will be 10 feet in width, length and height. Anything put in the pocket or taken out is not covered in your liquid unless you wish it to be.

The pocket has no oxygen and works in a similar way a portable hole does.  With the exception being you can store other magical bags inside yourself.

As an action you may transform your appearance or revert to your natural form. You can only change your appearance to one of the stored appearances from the Gluttonous Devourer trait. You are able to re-use stored appearances and only lose them when you wish to. Due to the magical nature your body holds now you are able to mimic everything about a persons physical appearance; including the feeling of skin, the softness of fur and anything else related to that creatures appearance. You are able to make minor changes to the appearance (limits set by DM) but not enough to be unrecognizable by others who may know them. You may stay in this form for as long as you wish.

Even tho you are able to change your bodies look you do not gain any physical traits the creature has other than sight, as you also no longer have blindsight, unless that creature has no eyes as well. You may choose to change into a creature up to one size larger than yourself but keep in mind you are still considered small and keep the same statistics you had as a slime. Clothing does not transform with you but if you have spare clothes in your Inter-Dimensional Pocket that fit what you are transforming into you may put them on during transformation, otherwise you will be nude.

Your fluid body allows you to move through spaces as narrow as 1 inch without squeezing. Non-magical restraints do not work on you, as you can just slip right out. Do to the fluid nature of your body, you cannot wear any armor or jewelry in your natural form.

As said before your body is made up of some kind of magic infused viscous liquid. You make a great conductor and you are able to pick your natural forms color.