That little green caterpillar that seems to bug you during your hunt for wild Pokemon in Pokemon Go could be a lot of help so don't ignore them. Caterpie is your friend, although at times you get too much of them spawning around, keep them, I'll tell you why.
According to Bulbapedia, our little friend Caterpie has yellow markings on its body aside from being a green caterpillar-like creature. It has a bright red osmeterium on top of its head, used to repel predators by releasing stench. The yellow markings also make Caterpie look like it has large eyes to scare off predators. It can walk almost on any surface with its suction cup shaped feet. Catepie is a vegetarian and its favorite is the Vermilion flower. That's some Pokemon trivia right there.
In Pokemon Go, Caterpie will have a maximum Combat Points of 433, its base attack and defense are 62 and 66 respectively. It has 90 for base stamina and can be hatched when walking 2 km. When tagged along as a buddy, it can collect a candy per 1km.
Common usage of Caterpie
Caterpie is meant to be weak, or at least seemingly weak. Its stats are low and are initially for starting players to use as a means of leveling up from the lowest levels. By evolving this creature, it can give a fair amount of XP, thus it is very useful for grinding at lower levels. Much like Pidgey and Weedle, Caterpie can evolve to Metapod at 12 candies and 50 further candies make it a Butterfree.
Throughout the main Pokemon series, our brave little Caterpie has been helping players at lower levels. It's sad to realize that this little creature is being forgotten once the players go mid levels to high.
Fighting the bigger Pokemon in Gyms
With the right moveset, you can pair an Exeggcutor with a Butterfree and win. With tackle that can do 10.91 DPS (damage per second), bug bite that can go as high as 13.89, and a charge move that unleashes an 8.85 DPs. As you can observe, most gyms would leave Exeggcutors on gyms, having a ready-to-fight Butterfree will solve that.
Fight or flee with Caterpie
Since Caterpie is a bug type Pokemon, it can stand up to Grass, Fighting, and Ground type attacks but do not expect it to do better with Fire, Flying, and Rock type attacks. As we all know, Pokemon Go still adapts the rock-paper-scissors game mechanics just like most of the game franchise does. Based on that information, you already know when to use a Butterfree when conquering gyms or just plain training with team mates. You also will have bragging rights afterwards, winning with just a Butterfree and all.
Most of us would go "pfffft! I can find it anywhere, it's common" but there are other areas that don't spawn as much. Bug types can be found where there are much plants like farms, gardens, grass, parks and the like. They are also easily found in populated areas that have strong mobile internet signal, or 'urban' places.