Pokemon has been around for over 20 years now, and in that time, some small changes have been made to individual Pocket Monsters. One such change was made to Charmander, though few fans may have noticed.
With Charmander's popularity, it was only a matter of time before someone picked up on the change. Charmander is one of the few returning starter Pokemon to Pokemon Sword and Shield, where it even nets a new form. But the change to Charmander's appearance is far older than that.
One attentive Twitter user, DrLavaYT, pointed out the change to Charmander's looks. In the original concept art design, starter Pokemon Charmander had small spikes running down its back, starting at the base of the neck. These spikes appear in art as well as the sprites for Charmander in Pokemon Green and Red, the Japanese original release of the games. However, the design never made it to the anime, and was eventually scrapped entirely going forward to new Pokemon games.
It's unclear why the change was made, though it may have something to do with Charmander's evolved forms. Since Charmeleon and Charizard lack the spikes, Game Freak may have decided that it made more sense for an unevolved form to not have a feature that would disappear on later evolutions anyway. Alternatively, the concept artists may have decided that the spikes made Charmander look less friendly or inviting to new players.
While the exact reason behind the change is a mystery, it's not the first time that Pokemon designs have undergone drastic improvements or changes. Concept art of rejected gen 1 Pokemon designs made the rounds previously, which showed some significantly different appearances than what gamers got to see in Pokemon Red and Blue. Other starter Pokemon, like Pikachu, have also gradually had their appearances changed over time, with Pikachu gaining a significantly slimmer appearance. However, unlike Charmander, Pikachu received a callback to this form with the recent release of Gigantamax Pikachu.
While Charmander's appearance has changed over time, its popularity hasn't waned at all. In addition to its comeback in Pokemon Sword and Shield, its evolutionary form Charizard received a Gigantamax version, further proving its lasting popularity with both players and the game developers.
Source: Twitter/DrLavaYT