This .NET class wraps the AcDbProxyObject ObjectARX class. 

This abstract class provides an interface to the description data for the objects stored within ProxyObjects in drawings.

Autodesk.AutoCAD.DatabaseServices.DBObject
    Autodesk.AutoCAD.DatabaseServices.ProxyObject

Public Class ProxyObject
Inherits DBObject

public class ProxyObject : DBObject;

ProxyEntity