#010: Caterpie
Graveler roll, Jigglypuff sing, Diglett dig, and Caterpie eat. Despite their small size, Caterpie are voraciously hungry. Shockingly, in a single year a Caterpie would eat more biomass than a Snorlax. Fortunately this is mitigated by the fact that Caterpie always evolve within a month of hatching. This is partly due to the natural tendencies of bug pokemon and partly due to the vast amount of energy they consume.
Caterpie crave variety, not just quantity and so rather than staying and eating a whole plant they keep moving as they graze, leaving Caterpie-wide trails cut cleanly through the vegetation. Viridian Forest is thick and tangled but passage has always been possible because of paths that are cleared by Caterpie. Travellers often complain about their maps being out of date, however and it's true that the route through is an ever-changing, winding maze, for Caterpie like to wander.
It is no coincidence that the authorities of Viridian and Pewter City have never had to discourage the forest encroaching upon civilisation. Instead, they are more concerned about Caterpie spreading beyond the forest, for if they ever reached farmland they would surely create a famine. Luckily, Caterpie have no desire to leave the safety of their dark home, for they know exposing themselves to the open skies would provide a free meal to the flying pokemon that prey upon them.
Pidgeotto and Fearow are usually agile enough to dodge a String Shot, so Caterpie must resort to deterrence instead of defence. The red horns of Caterpie were once assumed to be a weapon, to make the Caterpie's second move, Tackle, slightly less underwhelming. However, we now know instead that Caterpie can waggle their horns to mimic the forked tongue of an Arbok, a notorious predator and egg-eater.
Amazingly, this often works. Bird pokemon may be agile, but they are rarely smart.