In the beginning of the episode, there is a somebody in the top of the mansion that sees Scooby and the gang arriving. Who is this? No face was shown, and it did not look like it could be the Phantom Shadow. Was it Mr. Crawls?
The Phantom Shadow scares away cousin Simple, but how did he escape from the Phantom Shadow? The only way could have been through a window.
As to the above mentioned trivia regarding Colonel Sanders' Confederate uniform: there are many people that take part in Civil War reenactments. It is highly possible that the Colonel was one of these people. It is also possible that he was just obsessed with the Confederate ideals. He did, after all, have an extensive collection of clothing and equipment from the time period, as well as the Confederate money.
When the Phantoms are chasing the gang, two were chasing Shaggy and Scooby and one was chasing Fred, Velma, and Daphne. This makes a total of three phantoms, however there were only two of them.
During the scene where Scooby is explaining what happened to him, Fred starts off wearing his pj's. Then when the focus goes off, and then back onto him, he is wearing his everyday clothes. Then another focus change, and he is back in his pj's!
Adapted into the comic book story "Night For A Fright" (Gold Key issue #8, October 1971).
When Shaggy, Velma, and Scooby are on the drainpipe and it has just broken, catapulting them into the cave, the pole lands in the ocean, but the ocean is like glass. There is no splash!
The message written on the mirror in Cousin Simple's room was:
"The first one is gone, the rest will go, unless you leave the island and ROW!ROW!ROW! Phantom Shadow"
When the gang comes out to see what the noise in the hallway is and find Cousin Simple gone, it was midnight. They all peek out of their doorways and Fred, Shaggy, and Scooby are in their nightgowns, but Daphne and Velma are still in their clothes. They must have been sleeping in them!
In the portrait of Colonel Sanders, he is seen wearing what looks to be a Confederate uniform. Problem is, the war between the states occured in the 1860's not the 1970's! Colonel Sanders would have been an extremely old Confederate Colonel!
Fred is wearing pajamas when Scooby returns to the bedroom after the bathtub tipped over and dropped him into a pile of coal below the house. Notice the closeup on Fred when he said they should take a closer look at the bathtub. He seemed to be wearing his regular shirt with ascot. When they're in the bathroom though, he's still wearing the pajamas.
Shaggy is shown sitting down next to a completely empty fish bowl holding a sandwich. A few seconds later, when he grabs the fish food in which to season his sandwich, the fish bowl is full -- complete with water and an angry goldfish.
While Scooby takes a bath, he slips down a trapdoor into the basement, onto a pile of dirty, coal-like rocks, and into the path of a phantom. He can't get anyone to believe what happened -- even though he had to have been covered in dirt and/or soot.
Scooby's tag changes back and forth from yellow and blue to just yellow throughout this episode.
Cosgood Creeps: I am Cosgood Creeps, my partner Mr. Crawls couldn't make it tonight.
Shaggy: Creeps and Crawls! They sure picked the right lawyers for this job.
Fred: Four missing heirs, a haunted house, and a Phantom Shadow.
Shaggy: Like all that's missing is a spooky organ. (creepy organ music starts playing)
Velma: It's not missing anymore!
Velma: (referring to footprints) That's funny. If he's a phantom shadow, how come he leaves footprints?
Shaggy: Dirty feet?
Velma: I told you I'd save you.
Shaggy: Great, but next time please don't do my any favors.
Cousin Slicker: Ten o'clock and I suggest we all turn in.
Shaggy: Yeah, but into what?
Shaggy: Like, you would have to inherit a fortune, Scoob.
A sound byte of Big Ben chiming is used for the grandfather clock striking the hour.
The Green ghost appears in Scooby Doo Night of 100 Frights.
Culprits: Mr. Creeps and Mr. Crawls
Reason: They wanted to scare off heirs so as to keep control of the Sanders fortune.