Brock

Crystal Dragon:

One of Ash's best friends is Brock! He was once the gym leader of the Pewter City Gym, but now follows Ash on his journey. Brock's own goal is to become the world's best pokemon breeder.
He also has quite a soft spot for cute girls, and will become in his girl-crazy-mode every time he sees one. Most often he would do this in front of Nurse Joy and/or Officer Jenny.
His Japanese name is Takeshi and has no nicknames except the few times Ash calls him "Brock-O". (If I could make one up it'd be Brockoly!)
Brock's age remains a mystery. Some say he's 14, some say he's 16, some say....

Here is Brock's line up of Pokemon:

Geodude
Onix
Zubat
Vulpix

Brock Links

Chock Full O' Brock
Brock Rocks! Pewter City
Brock's Rug
Brock-O-Rama
 
 

June:

A good thing about Brock is that he makes up for a lot of Ash's stunted intellectual growth. Brock is always there to give helpful strategies and point out opponent's weak spots. 
Brock cares about Pokemon a lot, and is always looking for ways to make them healthier and stronger. 
His mother's death has caused him to be an excellent cooker and cleaner so he would properly take care of his brothers and sisters after his father left him. That is a plus for a Pokemon Breeder, and also one of the reasons he is admired by Professor Ivy.