The Plasmoid's Shape Self states:
As an action, 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. While you have a humanlike shape, you can wear clothing and armor made for a Humanoid of your size.
What confuses me is how much details the creature's "human-like" appearance can have... is it still an amorphous form, like Batman's Clayface? Is it a colloidal molded human like an anime slime girl or gummy bear? Or might it have the ability to render a detailed humanoid shape like a changeling's mask or the T-1000?
I might have missed the part where it clarifies, but from the artwork and use of words like "makeshift" and "humanlike," I'd suspect that it would gain the appearance of a humanoid only in the loosest sense of the word. Yet reading that it can wear all humanoid clothing and armour (including form-fitting full plate, necklaces, hats, masks, chokers, gloves, etc.), it sounds much more detailed...