I see everything in this thread, gosh darn.
Anyway, I keep trying to articulate just how not-special of a case Ridley's situation is. Just... FOR EXAMPLE, pretend you have a character that looks exactly like Ridley, but without the name attached or any knowledge of his abilities or physical PROPERTIES SUCH AS SIZE. Don't even imagine it's Smash. Could be any fighting game, just about. You're left with a character that has obvious playstyle potential, purely by his design alone. Coming up with a way to make him play interestingly would not be a challenge. Implementing his shape wouldn't be a problem, since he's mostly humanoid (I guess it's possible his weird neck could be a problem in SOME games, but I'll get to why that's practically not important).
If you don't have this idea that his size is somehow INTEGRAL TO HIS CHARACTER, then not only is he clearly feasible but also STILL A PRETTY INTERESTING CHOICE ANYHOW? And about how his shape doesn't matter: WE ALREADY HAVE A CHARACTER WITH EXACTLY THE SAME BASIC STRUCTURE IN CHARIZARD.
Now, let's add his name back. It's Ridley. The second most important character in a highly successful series, a series which could use another character in Smash, especially a character as highly requested as him. But, some people think it's a good idea to ignore all of that. All of his popularity, how interesting he could be, how feasible he is. Ignore it all, just because he's a bit big?
Ridiculous.