This episode features Robbie Amell playing a dog-like character named Scooby. He had previously played Fred in two live action Scooby- Doo movies.
The doctor seen checking Barney is actress Suzy Nakamura who also plays a doctor in Modern Family in various episodes.
The location where Barney "sees" himself meeting Nora and her parents is the Popover Pantry; the same location Marshall and his friend from law school, Brad (played by Joe Mangeniello), go for brunch in season 2.