But there are these sub-trends. I consider Scooby to be the ultimate macro-trend that defined a format. And that is a central character, mostly non-human and comedic, around which some hepcat teens have some adventures (mysteries, what have you).
This mold would explain at least the following: Scooby, Speedbuggy, Jabberjaw, Captain Caveman, Buford, Schmoo, and so on.

Now there's this sideshoot -- the small annoying character that is not necessarily centrail. Perhaps it is the Scrappy Doo prototype. I think Bat-mite was pioneering here. Orko. Godzooky from Godzilla. Gleek from Superfriends. Little cat from Inspector Gadget, and the like.

So there's "Central non-human Star that teens gather 'round" and "annoying small sidekick that is only comic relief."

Gadzooky was pretty bad too. I remember a pink dragon in the Flash Gordon cartoon, final season, I believe.

Gleek, Gleep, Bleep...except Bleep was cool.

I agree with all of this. I'd add Mighty-Man and Yukk to the macro-trend list, as well as Dynomutt; Dog Wonder (which often featured the Scooby Doo characters).

The Herculoids is a different thing altogether because it's a family unit assisted by multiple creatures, none of which are written as comic relief. I don't know if that makes The Herculoids some form of unique variant on the whole thing - they have some similarities with the Swiss Family Robinson, but are also clearly superheroes - or adventurers at the very least.

Space Ghost and The Mighty Mightor are more conventional superhero things and so is the original version of Bird Man (and the Galaxy Trio).

I don't know if I'm adding anything worthwhile to this discussion or if I'm only stating the obvious.

To understand the difference you are detecting, you have to recall that there was a sea change in American children's programming -- some kind of FCC regulation, or Surgeon General's warning, or somesuch -- in the late 60's or early 70's. Children's cartoons moved away from violence to problem-solving gangs of teens, and comedic central characters.

Herculoids and Space Ghost were before that, when some serious clobbering got done to solve the problem.

I think that's one reason that Justice League had to be packaged as "Super Friends" to get with the zeitgeist. And the long title "Spider-man and His Two Death-Dealing Partners, You May Choose to Die by Fire or Being Frozen" became "Spider-man and His Amazing Friends."

Was The Great Gazoo the original annoying sidekick character?

Only thing stopping him was he was a recurring character, but not a regular or semi-regular.

He was the original annoying FLOATING character (before Bat-Mite and Orko).

I feel that, in some way I cannot quite explain ... the floating is the most annoying part.

Was there ever a good version of this character archetype?

This makes sense - so The Herculoids and Space Ghost are like the missing links between Johnny Quest and Scooby Doo (or something)? There's still some clobberin' to be done but it's about to be phased out and there's a kind of transitional phase where we get stuff that's not entirely one thing or the other.

I don't know...I seem to recall Batmite also always being accompanied by some kind of sparkles, with Filmation's stock sparkly sound effect (AKA "Audible Gleam"). I feel pleasantly nostalgic recalling it now, but seems like that was kind of annoying too.

For me, I really think it's the voices of the characters.

Also, the way they smell.

One could detect an occasional bit of funk escaping from under that robe of Orko's. I think it must have made him sweat a lot.

If they get this movie right, Mattel will sell a LOT of action figures. It might be the new franchise that'll replace the now faded and jaded MCU.

I predict Wiig is going to eat and leave no crumbs.

If she's a robot, this could be difficult, but...well, I guess we'll see.

That's what will make it so impressive a feat.

No Cap!

Literally ICONIC

They were ALL good, IF you encountered them at that short-lived age where the character actually struck you as funny and interesting. I was about that age (8 or 9) when I first saw Bat-Mite. So I kind of liked him. Two years or so later, when Scrappy made his debut, I was outgrowing it. So I never became a Scrappy fan. And it was way too late for me and Orko to get along.