race features:
Darkvision:
You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.
Gelatinous Body:
Your body is, whether you are in your true form or in the form of a creature you have assimilated, made almost entirely of a firm gelatinous substance with a solid outer layer.
You are always considered to be an ooze for the purposes of spells and abilities, but while you have assimilated a humanoid you are also considered to be all creature types that humanoid was.
Wounds which do not result in the amputation of a body part are quick to close themselves, fully restoring their previous physical appearance at the beginning of your next turn in combat or after 3 seconds outside of combat. In addition, you are immune to any effect which would cause you to bleed or develop persistent wounds.
Bodily Reformation:
If any piece of your body is severed, you maintain control of whichever portion you wish that has at least 30% of you. If you are left with less than 30% of your body, you instantly die. Regardless of how apparently critical your injury might appear to be, you can harmlessly reattach each severed portion of yourself as an action so long as you do so within 10 minutes.
Your body can be regenerated at a rate of 10% of your body by refraining from strenuous activity for a week or being magically healed by 20 hit points over your maximum hit points.
Body Assimilation:
While in your true form, you can assimilate the remains of a deceased humanoid so long as you have their intact skeleton. During this process, which takes 2d4 days, you engulf the humanoid’s remains and slowly change your physical form to perfectly match theirs.
Once you have fully assimilated the humanoid’s remains, you gain the following:
Your physical form becomes that of the humanoid in both appearance and durability, holding their skeleton inside of your body. Only by closely examining your wounds or having truesight can another creature learn of your true form.
You replace your size and all movement speeds with that of the humanoid, which may result in you losing your ability to climb or gain the ability to fly.
You gain a racial trait of your choice from the humanoid that does not grant proficiencies or ability score increases. You may change which racial trait you possess at the end of a long rest, but you may only have one at a time.
You can abandon this assimilation during or after the process as an action, reverting to your true form. However, attempting to assimilate their remains will require you to fully repeat this process.