Your Charisma score increases by 2, and your Constitution score increases by 1

A newly created Oblex contains enough trace memories from its parent to ensure it can care for its basic needs on its own right away. Bone Collectors do not use age to determine ones adulthood but rather their overall size since it is directly related to how many memories they have consumed and memories often equal experience. Therefor some Oblex can mature faster than others. If left undisturbed, an Oblex can live on indefinitely without aging but remains susceptible to death by injury or affliction like anyone else.

Most Bone Collectors are trained killers who were carefully instilled with a sense of duty by the Drow that raised them in order to ensure that their assassins did not betray them. As a result, most  Bone Collectors view their word as their bond and will likely fall somewhere in or around the Lawful Evil alignment.

Unlike their pure-bred Oblex ancestors, Bone Collector Oblex never grow beyond the medium creature size. Bone Collectors grow incredibly slow compared to their relatives, making it easier for them to remain hidden. It rare for a Bone Collector to split.

You gain proficiency in the Deception skill

You can speak, read and write Common, Undercommon, and the primary language of whatever creature you are disguised as. If the creature cannot speak, you gain the ability to used limited telepathy to express simple ideas, emotions or images to creatures within 60 feet.

Due to your gelatinous nature, you can spend your action to successfully escape any non-magical restraint. You can also slip through a space as small as 1 inch without squeezing, though it is considered difficult terrain. Note that if your bones cannot make it through this space, they will be left behind and you cannot reform until a skeletal structure is acquired.

When you disguise yourself, you take on that creatures vision capabilities. When in your true form, you only have blind sight up to 60 feet.

When you are disguised, you take on that creatures movement capabilities. In your true form, your movement is 20 feet.

You have advantage of saving throws against poison and acid but disadvantage on saving throws against fire damage. If you fall unconscious, you must make a dc 10 Constitution saving throw or revert back to your gelatinous form. Death causes you to revert back instantly.

Starting at level one, you can cast the Detect Thoughts spell. This does not count towards your overall spell slots. If you successfully delve deeper into the creatures mind, you regain hitpoints equal to your level + your spell modifier. If the creature makes its save you are sent reeling back and gain nothing. 

At 1st level, you start out with one permanent form that you have taken the time to become familiar with. You have used your innate magic ability to preserve the bones and have memorized the form so completely that you can switch into it much faster than the others, so long as the bones are provided. Switching into this permanent form only takes one minuet and if your permanent form is disrupted for any reason while you are still touching the bones, you can reform using your action. You gain knowledge of the deceased creature's native language, general personality, sight and racial abilities but not its spells, secrets, clothing or any knowledge acquired through training. 

You can use this form indefinitely and switch back and forth between this form and others without any damage to the enchanted bones. You can only completely switch bone sets three times a day.

As your magical skill and proficiency in anatomy memorization improves, it will allow you to acquire additional permanent disguises so long as the bones are on hand and you have spent a long rest using your innate magic ability to protect the bones from your acidic nature before you use them for the first time. You gain an additional disguise slot at 3rd level and two more at 13th level. If you have reached the maximum number of permanent disguises, you can switch out an old guise for a new one by destroying the bones of the old body and enchanting a new set.

At 6th level, you learn the art of creation. By collecting choice bones and keratin, you can add onto your permanent forms however you see fit. This ability acts like an alter self spell and lasts until the new additions are broken or removed. Swapping bones and keratin takes one minute. Any horns, spines, claws, ect that are damaged in battle cannot be used again and must be replaced.

Once a day at 9th level you can take on the guise of any small or medium sized humanoid or animal whose bones you have absorbed. These bones must be in near pristine condition. It takes one hour to learn a new form while you dissolve the flesh and replace it with slime. In that time your true nature will be exposed. At the end of the creation process your appearance will be indistinguishable from the real thing aside from the faint smell of sulfur.

While in this form you gain access to all information the creature would freely share with a casual acquaintance as well as knowledge on how to speak, read and write the creatures native language. You also gain whatever type of vision it had. You do not gain its spells, clothing, racial traits, secrets or any trained ability.  

Any missing or damaged bones will lead to errors in the disguise. If you have never seen the creature in question in the flesh, you must make a DC 15 Intelligence saving throw to get the appearance right.

The disguise last for 24 hours or until you shape change again or sleep. After that the bones will no longer be considered pristine due to your acidic digestion.