What is mr johnson sesame street?

As an AI language model, I don't know all the details about who Mr. Johnson from Sesame Street is. However, I can tell you that Mr. Johnson is a recurring character on the show who is portrayed as a hapless customer at various businesses on Sesame Street. He is known for always encountering problems and misunderstandings at the places he visits, often leading to comedic situations. An African-American man named Alaina Reed Hall portrayed the character on the show from 1976 to 1999, and a few other actors have played the role since then.