Katherine Hillard Aka Kat was one of the villains on the series power rangers to have turned good.
Kat was originally a spy for Rita Repulsa and Lord Zedd. Kat had the ability to transform herself into a cat. As a child Kat was the brightest student in elemenotary school. When Kat was in high school she was on the swim team. Kat leaped off the high dive and almost drowned, that caused her to have a fear of the water. Kat was lured into a trap by a tenga warrior disguised as a human and put under an evil hypnotic spell by Rita Repulsa.
A ranger Castrophe
In order to gain the Rangers' trust, Kat transformed herself into a cat that was found and adopted by Kimberly. Kat had fallen in love with Tommy and became jealous of Kimberly. Kat was driving a car that was created by Repulsa to lure Tommy into a trap. the Rangers had managed to rescue both Kat and Tommy.
Changing the Zords
Rita's assistant Finster had found the location of the lost Zords. Rita and Zedd had deciced to use Kat to steal one of the Rangers powe coins in order to gain access to the white falcon zord. With the help of the Tenga warriors, Kat was able to steal Kimberly's power coin and sneak onto the white falcon zord. Kat knocked out Tommy and stole the white falcon zord.
A different Shade of a Pink
Kimberly was competing for the national swim championship. Rita had planned for Kat to distact Kimberly so that she would be too weak. Kat had a change of heart and saved Kimberly that caused Rita's evil spell over her to be broken. Rita and Zedd decided to get revenge on Kat for her betrayal by using Ninjor, threating to throw him in the water. Kat had decided to use herself as bait for the villains, but it backfired, Kat was captured and put near the stolen Pink power coin. Kat had managed to escape with the power coin and became the new pink ranger.