I’ve been considering how to make Scrappy work recently. His constant talking and over active attitude for some people can be annoying. But in my opinion, he is overhated.
So here is my solution, make him like Gromit. He doesn’t talk a lot, often letting his actions speak more for him. Scrappy would still be smart, still looking up to Scooby and being excited about facing monsters, but instead it shows in physical comedy. The gang would have to try deciphering him through this. A funny joke could be they try to have him write but his writing is only on dog language. Basically he’s still an over active and loveable puppy. Only he doesn’t talk like one of this auction guys.
And when he does talk, it’s either cute or important. As he’s Scooby’s young nephew he may still have trouble speaking. Maybe not in dog but in English he struggles, it’s is one of the reasons he admires Scooby. So he wants to show the gang and his uncle he can. But it takes practice before he can do it around others.
This could be him appearing as an adorable guest on occasion. Over time he learns new words from the gang, eventually making his first full sentence being gratitude to the gang and Scooby.