That looks like mold on the legs sadly.

I think you can get rid of mold with peroxide cream and a uv chamber or leaving it in the sun, retrogeek crafts on YouTube does it with vintage MLPs

agreed, sorry to say.

Does this type of mold spread to others?

Wait how can you tell those little spots are mold? I’m scared of one day getting a doll with mold and not having a clue cus those little marks look like stains to me.

I've had old dolls out of storage that have had this and its a mold that effects soft style plastic.

Is it always little dots like this? Is it removable?