I kind of want the lanky modern Frogger, but with arm/leg length being shorter, kinda like Mega Man where his classic look has the shorter/arms and length in Smash 4:
As for what he does differently from the old-school Frogger, I am not sure, I have not delved into that territory. The basic idea I have with his move-set is that it would involve him being a master at evading, being able to summon vehicles, logs, and fish for special moves. Frogger is one of the biggest icons in video-game history that aesthetically fits Smash Bros. well, and I would love to see Sakurai pull of a creative move-set out of the character, just like what Sakurai did with Pac-Man with his move-set basically being an amalgamation of classic Pac-Man history. An arcade match-up against Frogger vs. Pac-Man would be amazing! I know people like to bring up Bomberman as the 2nd/3rd Konami character, but I personally would rather see Frogger before Bomberman. I made a campaign for the character way back in Smash 4 DLC days:
Frogger is a choice I want to see so badly.