This "Poison Pin" pokemon is the first pokemon to technically have a gender. At the end of the it's name was a gender sign for either boy or girl, and each one looked differently and had separate evolutions based on male or female.
The second generations had the spanish way of making things sound masculine or feminine, while the final evolutions had royal names.

This "Patient" Pokemon can be considered an "Uber" pokemon because of it's cheap effectiveness. Only being able to use just use four moves no matter what may seem a drawback for it, but with the two moves "counter(deflects physical attacks back at the attacker with double the damage)" and "Mirror coat(deflects specaill attacks back at the attacker with double the damage)" it can take down opponents that are much stronger with it. And being able to have the third highest hp ever makes this pokemon incredibly cheap.

In the anime in the second season one starts to tag along with team rocket and becomes an annoying but valuable member.

Who's that Pokemon? (it appears in almost every cave or mountain anywhere.

This "Rat" pokemon is the standard weak little normal type of the first gen made to be severely weak for leveling and besides the rival battle and the first flying type it is one of the first pokemon you'll face.

Fun fact: In 2nd gen(gold/silver/crystal) this pokemon's role was replaced by sentret, third gen(ruby/sapphire/emerald) it was zigzagoon, 4th gen(Diamond/pearl/platinum) it was bidoof.

For your final question, here is the "???" or glitch pokemon. It is an infamous glitched pokemon that you can get only on red and blue and if caught it messes up some graphics. This pokemon is the true embodiment of evil and gaming errors.