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. Many fans speculate that they may, in fact, be the granddaughters of the sinister Clown Prince of Crime.

History
Harley apparently raised the twins herself (it is unknown what happened with their parents), having given up her allegiance to the Joker and having done her best to make them grow up as 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 attire consists of red wigs, white hats, red strapless tops, white shorts, red go-go 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 him 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, using his invisibility powers, he goaded them; second, lured them into walking over a floor slippery with jawbreakers; and, third, tricked 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. Harley ranted in disappointment, "You rotten little scamps! I struggled to make a good home for you, and this is the thanks I get?!" She swatted them in their rears with her cane as she continued, "Break a grandmother's heart! I hope they throw the book at you!" "Oh, shut up, Nana Harley," the twins responded in frustration.

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 and 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"