>>31715216>Venusaur is the only objectively perfect starter evolution line, as it's the only one to actually look like it's growing up.Venusaur does follow a logical maturation, but I'd argue that Charizard does that as well with the addition of that fantasy element which really ties into a good RPG adventure.
I do think the details of its growth were more prominent in the original artwork, where Charmander had that bump on its neck that moved to the back of it's head as Charmeleon, then split into horns as Charizard. They even played on that with Mega Charizard Y. That's just one of the less obvious touches, otherwise it just grows up and gets wings.