The Caterpie Line
Caterpie is a relatively cute Pokemon, and the first-ever bug-type encountered! Caterpie and its counterpart, Weedle, set the standard for early-game bug types: they evolve super quickly and will likely be the first on your team to do so, they have a middling first evolution, and a final evolution that starts off incredibly strong and only falls off as you progress further into the game.
Caterpie here is based off a Spicebush Swallowtail caterpillar, and the resemblance is...
...Uncanny, to say the least. It looks an incredible amount like its real world counterpart! Not gunna lie, I'd love to own a Real Life Caterpie, but can this one use Tackle? No.
Not a whole lot to say about Metapod! Beyond the fact of like, why do wild Metapod only know Harden? Didn't they evolve from Caterpie that knew Tackle too? That's always seemed weird to me.
Butterfree is so damn cute, and pretty useful in the early stages of your gym journey as well! It learns the ever-important Confusion very very early in a generation where psychic-type moves dominate everything else. Not to mention its cute little fangs and big ol' eyes! How could you not love Butterfree?