Animated Scrappy 1979-88
Scrappy Doo is the son of Scooby Doo sister, Ruby Doo. On the day he was born, he "played" with Uncles Shaggy and Scooby when they visited him and Ruby in the St. Bernard Animal Hospital (while the 2 were being chased by an orderly). Since then, he took a great shining to Scooby And Shaggy, wanting to travel with them when he was old enough. Something that eventually happened when he tagalong with the rest of Mystery Inc for some of their mysteries.
Scrappy Doo is pretty much what you expect from a hyper kid. He is very excitable about adventures and mysteries, and also a bit reckless. When danger or monster shows up, Scrappy is willing to face it head on, this leads him into a bit of trouble, like setting off trap for the monster and end up trapping the gang, or trying to face the monster himself (having Scooby and Shaggy picking him up in their getaways). He does mature over time, knowing when to run or following Scooby and Shaggy's lead into doping the monster with disguises and gags rather than just trying to fight.
Scrappy also idolizes both his Uncles Shaggy and Scooby, seeing them as brave and strong heroes and wishes to be more like them. He hangs with them the most out of the gang, and often literally drag them into doing things that they too scared to do themselves.
He also admires the rest of Mystery Inc too, and seems to pick up some of their talents and skills on some mysteries.
Through the Animated Series
Scooby Doo and Scrappy Doo (1979-80)
This shows introduces Scrappy to the Franchise. If the opening is to be hint how he became part of the gang, he delivered to Scooby via packaging train.
Scooby Doo and Scrappy (The Richie Rich/Scooby Doo Show/ Puppy Hour)
This series of cartoons were made shorter and focus more on Scooby, Shaggy, and Scrappy. Scrappy also teamed up with his Uncle Yabba Doo and Deputy Dusty in some shorts. Here, the monsters were depcited being real than crooks in costumes.
The 13 Ghosts of Scooby Doo
Scrappy is no longer the new kid on the team, as Flim Flam, a child salesman, helps him, his Uncles Scooby and Shaggy, Daphne and Vincent VanGhoul to track down the 13 Ghosts that Shaggy and Scooby unleashed from the Chest of Demons.
Scooby Doo and the Boo Brothers
Scrappy helps Shaggy solving riddles left by a deceased distant relative to get an inheritance.
Scooby Doo and the Ghoul School
While Shaggy and Scooby took up being coaches to Ms. Grimwood's Finishing School for Girls, Scrappy work as their aide. Here, Scrappy takes well to the spooky setting and makes friends with Matches, a small but hot tempered dragon of the school.
Scooby Doo and the Reluctant Werewolf
In this movie, Shaggy and Scooby are trick/stunt racers, and Scrappy helps with repairs and such, alongside with Ghoulie, Shaggy's girlfriend. This movie is the last appearance of Scrappy in the entire franchise, outside of comics and the live action movie.
Scrappy was featured promptly in select issues of the Archie's print of Scooby Doo comics, appearing at the start of the series run, but then began to appear only in a few stories until dropped before the series short run, when the license for Scooby Doo comics was picked up DC.
In the last story he appeared in, he help the gang catch a crook trying to undermine Los Vegas casino owners. He did this by brankrupting some of the casinos, earning millions of dollars and ownign buildings. It is implied that he stayed in Vegas, despite an angry Scooby coming after him after he pulled a trick on the gang when they were leaving.
Scrappy has yet to be seen within the series at all. He is only briefly mention in the letter box of issue 2 of Scooby Doo! Were the writers and editors of the book said that the fans can talk and ask about anything related to Scooby Doo... except Scrappy.
However, in the last issue of Cartoon Network Presents, it has a story focusing on Scrappy, teaching a pizza-delivery boy the ropes of teen sleuthing. This pretty much deabted as the best send off Scrappy has have from the main stream Scooby Doo franchise.
(Dis)honorable Mentions and cameos.
While being part of the franchise for most of a decade, Scrappy's appearance and involvement has been drastically downplayed with his lack of popularity years later. He barely seen or mention in any shows or movies since Reluctant Werewolf, and for most of them, outside of a cameo on a Supernatural episode, they seem vindictive to Scrappy in one way or another.
- Evening with the Scooby Gang- A meta-humorous animated short-feature on the DVD of "Aloha, Scooby Doo!". Fred brings up a "6th Member" of gang, to which everyone else cringes in horror and Shaggy saying how they're all agree to not talk about Scrappy. Fred then states he was talking about the Mystery Machine.
- In Scooby Doo and the Goblin King, when the Mystery Machine is put under a magical spell, turing into a monster that chases the gang on an amusement park pier, it runs over and destroys a prize stand filled with Scrappy plushies.
- In an episode of Mystery Incorporated, Fred and Daphne are looking at statues of some old friends, namely of Flimflam. The two then see Scrappy's statue. While Daphne is surprise to see it, Fred tells her to "look away. We all agree to never speak of him. Not ever."
- In the movie "Scooby Doo and the Curse of the 13th Ghost," which was to give "The 13 Ghosts of Scooby Doo" a proper conclusion, the entire movie seems to have completely removed him, as he not seen or mention durning the opening montage of the movie recapping the show. Near the climax, an teenager Flim Flam asks the gang about Scrappy, to which Fred and Velma looking genuinely confused and Velma asking "What's a Scrappy?"
2002 Live Action Movie
Before the movie
Told via flashback Velma. While she was recollecting Mystery Inc's golden age, how everyone was like a big happy family... then brought up Scrappy as the annoying nut of them.
Scrappy Doo was egoistical, pushing around the rest of the gang and calling them stupid (even Scooby). One day, he got on everybody nerves by declaring how he fight ghosts by himself, peeing on Daphne, and challenging Fred to role of leader; giving an ultimatum of being the gang's unquestionable leader, or he's leaving. The gang pretty much kicked him of the Mystery Machine and drove off without him.
Velma also stated despite of him shouting "Puppy Power", he wasn't really a puppy, but small due to gland problem.
In the movie
At the climax of the movie, it turns out the host of Spooky Island, Emile Mondavarious, and the one who reunited Mystery Inc after their break up was really Scrappy Doo.
Turns out that after he got kicked out of the gang, Scrappy went to Spooky Island to apply as for a job, but then took over, imprisoning and impersonating the real Emile Mondavarious. He then used the Daemon Ritus, a ancient demonic relic that summons demons and switch out souls/protoplasms of people. With the demons and some hired help, Scrappy planned to take over the world, using the park to steal the souls of visiting teenagers from around the world and replace them with demons in disguises; and brought Mystery Inc to witness, as well as getting Scooby as the pure soul he needs to complete the ritual to give him the power to do it all.
Scrappy used the Daemon Ritus and selection of the capture souls to empower himself into a giant monstrous demon version of himself, known as Scrappy Rex. To complete his transformation, he needed Scooby's Soul. After chasing Shaggy and Scooby around, Daphne manage to overpower one of Scrappy's goons, causing him to release all of Scrappy's captured souls and exposing his demons to sunlight,which destroys them. And while Scrappy was threatening the rest of the gang, Shaggy managed to separate the Daemon Ritus from Scrappy, causing him to lose size and power. In his normal state, Scooby just flicks Scrappy to the wall.
Scrappy's last line in the movie was "And I would've gotten away with it too, if it wasn't for you meddling sons of b-" and is cut off as he was taken to jail with the rest of his hired help.
Powers and Abilites
As his normal self, Scrappy is a small and weak Great Dane with a gland disorder. But with the Daemon Ritus implanted in his body, as well absorbing enough souls to empower it and himself; Scrappy grows bigger and stronger, as well as mutating into being like his demon army. It is unknown if he has any powers outside of his size in this form, or would there be if he had absorb Scooby's Soul. If he looses contact with the Daemon Ritus, Scrappy will lose all the souls and reverts back to normal.
Scrappy Doo is one of series of experiments of Smart Pets, to which he and other dogs were given cybernetic implants with different functions and features. He holds a grudge against Scooby Doo, as he was the prototype of the experiment who lead to the other dogs become what they are. He also was seeking Velma Dinkly, a scientist of the project, to help ensure his intelligence chip still functions properly and not burn out, leaving him like dog like the rest of the smart dogs in his pack.
While starting out as "normal" dog, Scrappy learned a function that allows him to use the nanites in the area to transform him into a bipedal humanoid dog with sharp claws.
Scrappy Doo is a firm believer of the survival of the fittest. Seeing himself and his pack of smart dogs surviving the chaos of the nanite apocalypse that has taken over most of humanity. He still has some level of compassion for other animals. As when he came across a malnourished normal puppy in a pet store cage, he wanted to take with and take care of it, but consider the fact that even if would live to be in better health; it would have become a monster like himself to survive the world as it is, something he didn't want any creature to endure through. So he gave it a quick mercy killing.
He also came across Cliffy, a one armed kid who was still normal despite of the nanites. Scrappy first saw Cliffy as a "pet". But seems to shows real concern for the kid's safety, either in signs of danger or seeing how Clif's 'survival supplies' were useless as they were just candy bars.