When Pokemon first hit the scene, it exploded it popularity not only in Japan but around the world. This Pokemania was entirely fueled by the first 151 Pokemon of the original generation, and it's impressive considering that many of the original Pokemon designs vaguely resembled their actual sprites in the games themselves. While there currently are debates surrounding the most recent titles in terms of how the Pokemon looked, much of the fun from the original Game Boy games was fueled by imagination and seeing how the actual designs looked in merchandise, anime, or other outside releases.
So it's no surprise to find out that there have been edits to some of the Pokemon favorites in the years since, and one recently pointed out by @DrLavaYT on Twitter notes that fans might have missed Charmander's subtle loss of spikes in its first appearance over the years.
Charmander's Lost Spikes:
In his earliest artwork and sprites, Charmander can be seen with spikes on his back. But these spikes were only present in Gen 1 -- Charmander's design was later revised, and his spikes were never seen again in any future generations. pic.twitter.com/eLMK1ic2gf— Dr. Lava's Lost Pokemon (@DrLavaYT) November 26, 2019
As @DrLavaYT point out, Charmander was seen with a few small dorsal spikes on its back that were only seen on its sprite in the original Red and Blue versions. While some art exists of this version, Charmander's spikes were removed from subsequent entries and adaptations. This is one of the many small revisions Pokemon has seen over the years with Pikachu's slimming down being another notable example.
Some fans have noted that Charizard's X Mega Evolution has those same spikes on its back, and might be a small nod to the original design. This would certainly be a fun idea and nod to the original continuity, but it seems like not many fans have minded the loss of spikes. Charmander remains one of the most popular starters to this day, and there's not a huge crowd out there asking for spikes.
Pokemon: The Series, is now airing new episodes weekly in Japan, but unfortunately is still not officially licensed for an English language release as of this writing. Staff confirmed for the new series include Daiki Tomiyasu serving as chief director for OLM, Maki Odaira as series director, Kunihiko Yuyama as creative supervisor, Shoji Yonemura overseeing series construction, Shuhei Yasuda serving as character designer, Masafumi Mima as sound director, Yuki Hayashi as series composer. Voice cast members include Daiki Yamashita as Go, Yuichi Nakamura as Professor Sakuragi, Kana Hanazawa as Koharu, Megumi Hayashibara as Jessie, Shinichiro Miki as James, and Inuko Inuyama as Meowth.