Corphish is a complete and utter Good Boy.
This impeccable specimen also holds a secret, that being no one actually knows what region Corphish originates from. Nice try wise-guy, it isn't Hoenn. Apparently they were imported form "overseas" TO Hoenn where, being the hardy boys they are, they quickly grew in number and now drive pokemon out of ponds and are OK with eating whatever.
The best part is the REASON they were imported to Hoenn in the first place: to be pets. Yessir, these dog-sized crawdads apparently made great pets. I for one find the people within the pokemon universe suddenly a lot more relatable.
It can only be caught by fishing in the Gen 3 games, which makes sense. Crawdads aren't exactly "floaty" to put it scientifially, so you'd never see one while using surf. Despite its apparent common and invasive nature, Corphish is surprisingly not too prevalent of an encounter in Ruby and Sapphire, only appearing on two routes. Maybe it just hides better in the other ponds.
Strangely enough, the Black and White games, but this time it can ONLY be encountered by surfing. Fishing won't work. This is likely for the more mechanical reason that B & W had EXTREMELY few different surfing encounters and Corphish was simply used to round out the numbers. Here wee already a good varied balance of fishing encounters.
Most hilariously though, is how you encounter it in Diamond and Pearl. It is found in exactly one body of water. This one in Celestic Town.
It isn't cut off by much, its just that small. Corphish exists solely in this pond in Sinnoh. Which is hilarious.
Corphish is more than just a charming face. Having used one I hatched from an egg for an entire playthrough of Platinum (I traded for the egg early game) I can vouch for it's usefulness. Hyper Cutter is an ok ability in-game. Corphish doesn't lack decent moves either, learning them at an acceptable pace as you move through the game. Crawdaunt is also a powerhouse, but he'll get his own "Talk About" don't you worry. Though funnily enough, despite Crawdaunts constant rage, Corphish is never said to be aggressive in the slightest.
Corphishs name is a weird spot. The "Cor" could come from "corps" given its apparent populousness, and "phish" simply comes from the fact that it is a crayfish. His Japanes name means "Bad Habit Army Crayfish." Beautiful.
Want a fun Corphish fact? Trick question, all Corphish facts are inherently fun. Corphish is the ONLY pokemon to date with a capture rate of 205. Special fellow.
Its also pretty great that Corphish has no real way of moving its claws. The "arm" oh the claws is so short that it can only really hold them in a constantly confrontational pose. What other pose is needed really?
Corphish lacks the dark-typing of its evolution, largely because while it is still a bitey and rowdy boy, they have not yet delved into full on ne'erdowell territory. They share the same abilities though, Battle Armor and Hyper Cutter being the regular ones. While fitting abilities neither is great, but ultimately the dream world ability is WAY better: Adaptability. Increases STAB, and when combined with a high attack and defense stat as well as some really nice moves (Aqua Jet, Crabhammer, Knock Off, Swords Dance/Dragon Dance) Corphish cleans up pretty nicely in the Little-Cup as a decent wallbreaker.
The largest question left by Corphish is whether or not we will ever get to see its true home? Maybe its a mystery best left unanswered.