He is a villain who only appeared in "The Suavest Spy". He is the most devious thief. Katz only works when there is a new moon and the Earth is aligned with Venus for total darkness. He is a thief that WOOHP has never caught. He nearly stole all the most valuable jewels in the world. He is an expert at seducing women (which is the reason why the girls liked him). He knows all about WOOHP, Jerry, and the girls for some reason. He planned to steal the great pearl of Uzbekistan.
He appears to take pictures on the secret vault which is the pearl of Uzbekistan is been kept in the middle of the night and it was his plan to steal it. The girls are sent to capture Katz but he is able to trick the girls while they are observing him from his estate where he prepares their favorite muffins and also to give the girls a car chase in the middle of the night to capture him but they ended up failed due to being fell in love from his cool looking appearance while escaping using the para glider as he continues to take pictures for his target that he had planned to steal. Later on he is seen dancing with Clover in a formal party occasion but they are unaware that he is good at seducing the trio. Katz gives Clover a necklace and he put it on her neck and Sam realizes it was really him after all. Katz activates Clover's magnetic ring to steal the key for the great pearl of Uzbekistan soon after all the audience give a round of applause he leaves the scene making the girls fail to capture him.
When Jerry scolds the girls for not capturing him due to his cool looks and his appearance, they are immediately sent to the place where Katz is about to steal the pearl of Uzbekistan. He was seen managed to get inside and make it to the vault. He uses his shoes to avoid being caught and uses the key to release the vault knowing of the passcode. He got caught up by the girls who are hiding the vault, as they are guarding the pearl of Uzbekistan. Katz quickly gets the pearl and lock the girls from the vault and leave. The girls tried to get out of the vault as Sam uses the M-Ray Contact Lense and found the place to get them out of the vault as Clover hits using the Magnetic Laser Mood Ring. After this they manage to get out of the vault after using the ring to control the lock pass code. They are now pursuing Katz using their Jetpack Backpacks. Katz became confident to be chased by them he gives them a chase. Clover manage to caught his jetpack shoe using the Magnetic Laser Mood Ring. He demands to let him go as Clover deactivates her mood ring and causes him to crash into the garbage. When the girls finally caught him he tries to seduce them again to do his dirty trick. But to his dismay, Clover tries to seduce him but to counter his seductions towards them as she lets him fall on the ground, hurting him.
He was finally arrested by Jerry and his men from WOOHP and the pearl is recovered. Before he was taken to WOOHP prison, Katz gave the girls a one piece of red rose and threw at them to make the girls fight each other for the rose.