When was Pseudo Slang created?

There is no slang term known as "Pseudo Slang". It's possible there's a misunderstanding or you're referring to a term that has a different spelling or a more specific context.

Could you please clarify what you're looking for?

For example, are you referring to:

* A specific slang term with a slightly different spelling?

* A particular type of slang, such as "mock slang" or "fake slang"?

* A linguistic phenomenon related to the creation and evolution of slang?

Providing more details will help me understand your question and provide a more accurate answer.