In computer programming, a poltergeist (or gypsy wagon) is a short-lived, typically stateless object used to perform initialization or to invoke methods in another, more permanent class. It is considered an anti-pattern. The original definition is by Michael Akroyd 1996 - Object World West Conference:
A poltergeist can often be identified by its name; they are often called "manager_", "controller_", "start_process", etc.
Sometimes, poltergeist classes are created because the programmer anticipated the need for a more complex architecture. For example, a poltergeist arises if the same method acts as both the client and invoker in a Command pattern, and the programmer anticipates separating the two phases. However, this more complex architecture may actually never materialize.
Poltergeists should not be confused with long-lived, state-bearing objects of a pattern such as Model-view-controller, or tier-separating patterns such as Business-Delegate.
To remove a poltergeist, delete the class and insert its functionality in the invoked class, possibly by inheritance or as a mixin.