You take up your entire space. Other creatures can enter and exit your space as if it were difficult terrain, but has disadvantage on the saving throw if you use Engulf.
Creatures inside you can be seen but have total cover.

Acid Blast. You learn the acid splash cantrip and the vitriolic sphere spell. Once per long rest, you can cast it without expending a spell slot. You can also cast it using any spell slots you have. The spells' spellcasting ability is Intelligence, Wisdom, or Charisma when you cast it using this trait.

Acidic Composition. You are immune to acid damage and resistant to poison damage. Anything of your choice that ends its turn within reach or inside of you takes 2d4 acid damage.

If you are reduced to half health or below, your size decreases to Medium. If you are reduced to below one-quarter health, your size decreases to Small. If your health reaches 0, your size decreases to Tiny.

You have blindsight to 60 ft. and are blind beyond this radius.

You can create up to three pseudopods from your material. The total length of the pseudopods can be up to 5 ft. Thus, you may create one pseudopod that is 5 ft. long, five pseudopods that are each 1 ft. long, or anything in between. Pseudopods function as manipulators.

You may move forward at your movement speed into enemies, covering them with your body.

If you are playing a spellcaster, your race gives access to a number of acid-related spells, even if you would not normally. Spells that affect or deal multi-type damage, such as Chromatic Orb, may only be cast for acid damage when learned via this feature.

Your gelatinous body is capable of reverberating at specific frequencies, giving you the ability to replicate any noises you have heard before. As such, you know all languages that have been spoken to you continuously.