Alright, I would like to ask all members to help put together a cool little trivia activity! List facts interesting facts about Pokemon that may have not been known to others!
I'll start with 25 cool facts!
#1: In Red/Green Beta, Venomoth was originally Metapod's evolved form, and Butterfree was originally Venonat's evolved form!
No proof to this. Just speculation.
#2: In Red/Green Beta, Eevee's original name was Eon, explaining the suffix on it's evolutions.
#3: Girafarig's name is a palindrome, which is based on the original art of Girafarig having two heads on each side rather than just a tail with a head.
#4: Jesse and James are actually only 17 years old.
I don't think this is canon, but I recall it being mentioned by an American VA.
#5: Episode 035 of Pokemon was banned in the US due to too many guns shown in the episode.
#6: Following that, Episode 037 was banned worldwide by the Japanese Government from causing over 700 seizures in Japanese children.
#8: Jynx's face color was changed from black to purple because many believed it adhered to racial stereotypes.
Actually, it was only one lady who filed a lawsuit - same reason there hasn't been a Kadabra card since Skyridge - one guy.
#9: Mew was trademarked on May 9, 1990. This was before Pocket Monsters had even been trademarked (September 11, 1995).
#10: On the topic of Mew, Nintendo had originally not known that Mew was programmed into Red/Green. It was found by hackers.
Don't know if "hackers" is appropriate, but this is mostly true.
#11: Snorlax was thought to be the fastest Pokemon until disproved in 2004.
....what? who the hell though that? Do you mean fattest and/or heaviest? By that logic, Groudon isn't heaviest either, as somebody could come out and disprove it.... and R/S came out in 2003.
#12: Kangaskhan was originally an evolved from, but the basic Pokemon was scraped during production.
No proof...
#13: Pokemon Black and White were in production before Platinum was even released!
#14: Spinarak isn't even a spider, since it only has six legs.
Squirtle isn't a turtle either, since it spits water and can use its shell as a weapon. 
#15: Though Flying type is a common second typing to Bug types, the only Bug types that can learn Fly are Genesect and Volcarona--which aren't even part Flying type.
#16: After battling a girl in Generation I, she will say that she would love a Pokemon that was pink and had a floral pattern. Eventually, this Pokemon was introduced in Generation V (Munna).
#17: The Flying type was originally called the Bird Type.
#18: There is an item that has been "dummied out" of the game called ?????, which lets the player Surf without using a Pokemon. This leads many to think that originally the player had a Surf board, rather than using Pokemon for surfing.
#19: Jigglypuff's prototype name was Pudding, while Wigglytuff's prototype name was Custard.
#20: Abra's prototype name was Hocus, and Kadabra's Pocus. It was most likely changed to represent "Abra Kadabra, Alakazam".
#21: Tentacruel's prototype name was "Man O War".
#22: Cubone's prototype name was "Orphon", which explains why its called "The Lonely Pokemon".
#23: Trainers were not originally given names. Instead of "Hiker John wants to battle!", it was, "THE HIKER wants to fight!"
#24: Pokemon Gold and Silver was originally going to be called "Pocket Monsters 2" or "Pokemon 2".
#25: In Generation III, Pokemart roofs were originally going to be colored red. They were most likely changed to avoid confusion with a Pokemon Center.