Shaggy and Scooby sleep over at Doo Manor, where they encounter Nasty-Doo, the ghost of Scooby's cursed relative Nasty Doo, and he is out to turn the curse on Scooby. The only way to stop it, is for them to leave Doo Manor forever!
Shaggy and Scooby are having a sleepover at Doo Manor. After eating all the pizza and watching TV, they decided to go to bed, so they could have breakfast sooner. However a dog-like monster emerges from the empty pizza boxes and walks towards them.
The monster chases them to the diving board of the pool and dives after them, but Scooby blows an inflatable tube and the monster lands in it, then Scooby deflates it sending the monster out the window. Scooby's parents than came into the room, asking for his help, his mother saying they're being chased by a W E R E D O O. Shaggy asks if she means a Were-Doo, which causes the Doo's to faint, Shaggy then calls the gang for help.
After Velma then wakes them up with a pizza, they told them that for unknown reasons, the monster just showed up at Doo Manor and chased the Doo's away. Freddie promised that the Scooby-Doo Detective Agency will get to the bottom of it, ordering their next stop to be Doo Manor.
Upon arriving, they meet Professor Digmi, who's researching the history of the Doo's. He explains that the Doo's ancestor Nasty-Doo once upset a sorcerer who turned him into a monster. He goes on, explaining that the curse will be passed on to the first son of every seventh generation, upon setting paw in the manor during a full moon. Velma calculated that's Scooby the first son, and theirs a full moon outside the manor. But the Professor says that the curse will end if all the Doo's abandon Doo Manor and never returns. After he leaves, Freddie says the gang will break the curse and save Doo Manor. Scooby's parents thank their son for helping. The gang then splits-up to search for clues.
Velma, Shaggy and Scooby went to Scooby's Uncle Horton's lab for help, but run into Nasty-Doo instead. After they lost him, they finally found Horton, who shows them his interests in scary things, which led Shaggy to believe Horton's the monster.
They ran into the rest of the gang and told them that Horton is the monster. Shaggy notices and thinks that Scooby's is turning into a Were-Doo, which cause the latter to faint, and it turns out he had a mop on his head. After Daphne wakes him up with a Scooby Snack, he leads them to a bookcase, which opens a secret passageway. Upon opening, Nasty-Doo emerges from within, and corners the gang.
Chasing the gang into the next room, they throw him a Birthday party, much to the monsters confusion. They then blindfolded and tie him up, getting him ready to play pin the tail on the donkey, they make him spin like a top, causing him to crash, and track dirt on the floor. They led him to the passageway behind the bookcase, playing hot or cold. After the monster leaves dazed, the gang immediately escapes.
They ran into Digmi, who drops a birthday hat from the gangs ruse. He than leaves to work on a theory, but tells Scooby that he hasn't become a monster yet. They than meet Gilda Squater, who has a grudge against the Doo's. Leading them to her room, she explains that she lived in the Manor when the Doo's inherited the family home in a will, she didn't want to be kicked out by dogs, so she's protesting against them. She than throws them out and upon seeing the moon, Scooby begins to worry that he'll become a monster. But the gang assures him that even if he was big and scary, he wouldn't be so bad. Than Nasty-Doo appears behind them and a chase ensues all over the manor.
They lost him by hiding in the basement. Scooby fell into a big hole and emerges with his head looking like a monster. But Velma says that he's only wearing a mask, much to everyone's relive. Velma than solves the mystery and comes up with a plan to trap the monster.
The gang (except Scooby) are digging a way out in the basement when Nasty-Doo shows up, but they say they're not scared of him anymore, but another monster. Scooby then appears wearing a Were-Scoob suit and engages Nasty to see who's scarier. They had a watermelon eating contest, but Scooby eats Nasty's and loses his mask, he puts it back on the wrong way and falls into the hole. Nasty goes for the gang, but Scooby digs a hole surrounding the monster and the floor gives away taking him with it.
The gang wonders who the monster really is. Shaggy thinks that he's Horton-Doo because he's weird and spooky, while Daphne thinks it's Gilda Squater since she hates the Doo's. Freddie says that the monster is really Red Herring, who than gives him a Golden Weenier award for accusing him for something Red didn't do 10,000 times. Velma than masks the monster saying he's really Professor Digmi. She first suspected him when the monster tracked dirt where the Professor was digging, than the Professor dropped the monster's Birthday hat, and she knew for sure he was the culprit when Scooby found the monster's costume where the Professor was digging. He was trying to find a missing leg bone for a skeleton of a Doo's ancestor, which would've made him famous. Upon Digmi taken to prison, Velma assures Scooby that the Professor made up the whole curse to scare away the Doo's. Freddie is glad Scooby won't turn into a Were-Doo, but the latter faints again. Shaggy says that no one can handle family curses better than Scooby-Doo.
- Newscaster (final appearance)
- Red Herring
- Police officer (single appearance)(no lines)
- Missing Link Doo (single appearance)(skeleton)(deceased)
|Horton-Doo||He is weird and spooky.|
|Gilda Squater||Doo Manor belonged to her until Mr. & Mrs. Doo received it in a will.|
|Professor Digmi as the Nasty-Doo||To dig up a leg bone.|
|Don Messick|| Scooby-Doo|
|Casey Kasem||Shaggy Rogers|
|Christina Lange||Velma Dinkley|
|Kellie Martin||Daphne Blake|
|Carl Steven||Freddie Jones|
|Scott Menville||Red Herring|
|Rob Paulsen|| Nasty-Doo|
|"He's a Were-Doo Wolf"||Credits||Performed by|
The following credits are how they are seen on-screen (or as close as possible).
- Executive Producers: William Hanna & Joseph Barbera
- Co-Executive Producers: Paul Sabella & Mark Young
- Executive In Charge Of Production: Jayne Barbera
- Producer: Craig Zukowski
- Associate Producer: Scott Jeralds
- Story Producer: Bill Matheny
- Creative Design: Iwao Takamoto
- Supervising Director: Ray Patterson
- Animation Directors: Joanna Romersa, Allen Wilzbach, Joan Drake, John Walker
- Directors: Don Lusk, Carl Urbano
- Recording Director: Gordon Hunt
- Voices: Rene Auberjonois, Victoria Carroll, Bernard Erhard, Barry Gordon, Pat Harrington, Casey Kasem, Christina Lange, Marilyn Lightstone, Kellie Martin, Scott Menville, Don Messick, Lynne Moody, Pat Musick, Rob Paulsen, Robert Picardo, Carl Steven, B.J. Ward
- Animation Casting Director: Kris Zimmerman
- Talent Coordinator: Lynne Batchelor
- Title: Scott Jeralds, Tom Ruegger
- Graphics: Iraj Paran, Tom Wogatzke
- Graphics Assistant: Parvis Parandoush
- Music & Songs By: John Debney
- Director Of Music Production: Bodie Chandler
- Design Supervisor: Scott Jeralds
- Unit Head: Scott Hill
- Character Design: Eric Clark, Denise Shimabukuro, Virginia Hawes, Pete Alvarado, Jr.
- Design Paste-Up: Viki Kirch, Dana Granger
- Design Assistants: Barbara Krueger, Jesus Rodriguez
- Animation Supervisor: Frank Andrina
- Key Layout Artist: Jim Hickey
- Background Supervisor: Al Gmuer
- Background Artists: Jim Hickey, Patti Palmer, Ruben Chavez, Ron Roesch
- Xerography: Star Wirth
- Ink & Paint Supervisor: Alison Leopold
- Color Key: Suzette Darling
- Animation Checking Supervisor: Jan Adams
- Animation Checking: Beth Goodwin
- Production Coordinator: Vicki Casper
- Production Supervisor: JoEllyn Marlow
- Production Assistants: Tori Pollock, Sandy Benenati, Nancy Grimaldi, Olivia Knighton, Debby Lathrop, Janet Mazzotti, Margot McDonough, Valerie Menk, Linda Moore
- Word Processing: Gail Prewitt, Linda Germain
- Supervising Film Editors: Terry W. Moore, Gil Iverson, Tom Gleason
- Editor: Tim Iverson
- Music & Sound Editing: S.V. Editorial
- Track Readers: Jim Hearn, Kerry Iverson, Kay Douglas, Carol Iverson
- Sound Direction: Ed Collins
- Re-Recordin Mixers: Ezra Dweck
- Negative Consultant: William DeBoer, Jr.
- 'Production Supervisors: Wayne Dearing, Bob Marples
- Produced In Association With: Wang Film Production Company, Ltd. and Fil Cartoons, Inc.
- Studio Operations Executive: Bennett E. McClellan
- Progam Administrator: Annie Montgomery
- Production Publicist: Tom Brocato
- Copyright © 1991 Hanna-Barbera Productions, Inc,
- All Rights Reserved
- The events, characters and firms depicted in this photoplay are fictitious. Any similarity to actual persons, living or dead, or to actual events or firms, is purely coincidental.
- Hanna-Barbera Productions
- This is the last full-length episode.
- Scooby is once again wearing boxer shorts.
- This episode, as well as the previous one, show the title card directly after the theme song, unlike other season 3 episodes.
Animation mistakes and/or technical glitches
- When Scooby notices the full moon outside for the final time and grieves about being "cursed," the moon actually disappears on-screen after a few seconds.
- During the scene where Scooby-Doo (dressed up as a "Were-Scoob") and Nasty-Doo confront each other, as they wave their arms they briefly grow multiple arms in the process.
Inconsistencies/continuity errors and/or goofs/oddities
- None known.
- A Pup Named Scooby-Doo: Volume 7 DVD released by Warner Home Video on August 17, 2007.
- A Pup Named Scooby-Doo: Complete 2nd, 3rd & 4th Seasons DVD set released by Warner Home Video on March 18, 2009.
- Scooby-Doo! and the Werewolves DVD released on October 23, 2012.