Katie

KT, or Katie, was a relatively late addition to AJ's party during Twitch Plays Pokemon: Crystal. Katie was originally a Dratini that was given to AJ in Dragon's Den. She evolved into a Dragonair at 8d 0h 13m and finally, a Dragonite at 11d 8h 27m.

Name
Due to being a female and receiving the name KT, it was very easy for the community to accept the name 'Katie'. This was a relatively plain sounding name, but fit well with others such as Brian.

Personality (Lore)
Katie joined the party as a lowly Dratini and a member of the Dragon Type family which had become somewhat ridiculed thanks to the efforts of Red and his All Terrain Venomoth two years prior against the Elite 4 member Lance.

Many people in the community believe that Katie joined AJ's party to restore honor to dragon Pokemon. She was viewed to be on a quest to defeat ATV, the Dragonslayer, for disgracing her Type in single combat against Lance's Dragonite. This was the motivation that allowed Katie to become a truly powerful member of the Gen 2 team and contributed greatly to the overall success of Gen 2.

When AJ fought Red in Generation 2, Katie and ATV were said to have a rivalry, ATV being the Dragonslayer and Katie being a Dragonite. Katie eventually defeated ATV.