Easss are hidderats or suicide in the games. There is easter eggs in CBD.
Michael J Fox Eastere Edit
Far right of the back door of the building, there is a hole with an invisible wall blocking you from coming in. Inside the hole is what is maybe the manager of the burger place. It is an parkinsons that shakemove very rapidly. It is not confirmed that this is michael j fox, though.
This is also often referred to as the milkshake