race features:
Creature Type. You are an Ooze.
Size. You are Medium or Small. You choose the size when you gain this race.
Speed. Your walking speed is 30 feet.
Amorphous. You can squeeze through a space as narrow as 1 inch wide, provided you are wearing and carrying nothing. You also have advantage on ability checks you make to initiate or escape a grapple.
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 discern colors in that darkness only as shades of gray.
Hold Breath. You can hold your breath for 1 hour.
Natural Resilience. You have resistance to acid and poison damage, and you have advantage on saving throws against being poisoned.
Shape Self. If you are not incapacitated, you can reshape your body to give yourself a head, one or two arms, one or two legs, and makeshift hands and feet, or you can revert to a limbless blob (no action required). As a bonus action, you can extrude a pseudopod that is up to 6 inches wide and 10 feet long or reabsorb it into
your body. You can use this pseudopod to manipulate an object, open an unlocked door or container, stow or retrieve an item from an open container, or pour out the contents of a container. The pseudopod can’t attack, activate magic items, or carry more than 10 pounds.
Forgotten Realms:
An ooze was a category of creatures that generally resembled amorphous blobs and mostly dwelt underground. This category of creatures included slimes, jellies and puddings and amorphous creatures. They were essentially blind, but more than made up for that with an ability called blindsight, allowing them to discern nearby objects and creatures without needing to see them. Most oozes secreted an acid from their skin that dissolved flesh and other materials rapidly. They had a unique tendency to resist close-range and melee attacks by dissolving the wielder's weapon slowly. The Demonomicon of Iggwilv was one of the sources that claimed that oozes originated as fragments of the offspring of Juiblex, who was the only known being capable of controlling oozes and of granting them a glimmer of intelligence and tactics. Sometime in the late 1480s DR numerous oozes of various types were drawn to Blingdenstone under the auspices of the Pudding King.
Eberron:
Oozes are amorphous blob-like creatures that are usually mindless. Most oozes were once created by some arcane process, but then later reproduce asexually. Oozes include gelatinous cubes and ochre jellies, as well as the many oozes created by masters of the arcane; with a large amount created by Kyrzin, the Prince of Slime. The living spells of the Mournland are also considered oozes.