My cousins are all police officers, all of us look identical, plus we're all named Jenny."
–Officer Jenny about her family
Officer Jenny (Japanese: ジュンサーJunsar) is a police officer who lives in every city. They can be told apart by Brock. She uses Growlithes and Arcanines as police dogs to search thieves.
Originally they had blue hair until "Here's Looking At You Elekid" when the animation changed to digital effects changing their hair green.
The Japanese name, Junsar, means "police officer". The Jenny officers often accompanied by Growlithe, to use as a police dog (although there are exceptions, like one had a Spinarak or where another has a Meganium, Parasect and Tangela or one that has the Squirtle Squad, etc.). There are some other minor differences between each of them, but not many as the Joys. The only differences are the symbols in their caps and uniforms (which are different depending on your region). Unova Region Jennies have the back of their hair and their bangs cut.
One Officer Jenny from the Kalos region fell under the control of a rogue Malamar and assumed the identity of Madame X on its behalf. This Officer Jenny had no clue what she was doing, but discovered that Malamar was using her to begin reviving the Ultimate Weapon.