Dee Dee

Twin sisters Delia and Deidre Dennis were the granddaughters of Harley Quinn, who joined the Jokerz under the joint alias "Dee Dee" and later followed in their grandmother's footsteps as "hench-wenches" of the original Joker. It is speculated amoung fans that they may, in fact, be the grandaughters of the Joker.

History
Harley apparently raised the twins herself (it is unknown what happened with their parents), having given up her allegiance to the Joker and doing her best to make them grow up normal kids. She failed. Delia and Deidre inherited Harley's earlier fascination with the Joker, and joined his namesake gang while still in their early teens. They are identical, both have long blond hair and blue eyes. Their attires consist in red wigs, white hats, red strapless tops, white shorts, red boots and make-up.

Dee Dee, along with Bonk, Chucko,Woof, and Ghoul, were recruited by the resurrected Joker for his plan to attack Gotham City. On his orders, the Jokerz stole advanced technology from a series of warehouses.

In the gang's first confrontation with Batman, the young Dark Knight made the mistake of taking them for inconceivable and useless girl "helpers". As soon as he turned his back on them however, they attacked with an amazing blend of skill, ferocity, and coordination.

Appearing as their "normal selves" they later attacked Terry in a nightclub, and he barely managed to avoid them.

In the Jokerz' last confrontation at the Jolly Jack Candy Factory, Batman fought smart: first he goaded them using his invisibility powers, lured them into walking over a floor slippery with jawbreakers, before tricking them into charging into each other, knocking themselves out.

The twins were arrested. They were bailed out into Harley's custody while awaiting their trial, as Harley ranted about what disappointments they were to her.

Alternate Timeline
In an alternate timeline, Dee Dee and the other Jokerz were recruited by Chronos as enforcers, and upgraded with radically advanced technology and weapons, giving them actual superpowers. In this time-stream, Dee Dee reportedly killed Kai-Ro.

In another battle with the Justice League Unlimited, they succeeded in killing Terry as well.

Powers & Abilities
The twins were Olympic-level gymnasts and experts at tumbling and hand-to-hand combat.

In the alternate timeline, the twins were able to multiply themselves at kinetic impact, and carried powerful energy whips capable not only of releasing said energy into targets ensnared in them, but which also had the ability to pierce the shields and constructs of Green Lanterns with ease.

Appearances

 * Feature film Batman Beyond: Return of the Joker
 * Justice League Unlimited
 * "The Once and Future Thing Part One: Weird Western Tales"
 * "The Once and Future Thing Part Two: Time, Warped"