Shimmer was Kobra's right hand and the twin sister of Mammoth.
Shimmer is a young Caucasian woman with short, red hair and green eyes. The right half of her head is bald, and adorned with a black Kobra-tattoo. She uses blue lipstick and wears several earrings.
In 2010, she wore sleek, black pants and a blue top with long, black gloves connected to her shoulders.
By 2016, she took to wearing cargo pants and heavy boots, and has a belt with a plain, gray buckle and a holster for a machete. She also wears a black, high-cut, one piece swimsuit. She has a small, black band around her left elbow and black, fingerless gloves.
Kobra kept her by his side, and confidently ordered her to one on one combat with Robin. They were evenly matched, but Robin was forced to retreat. When he went after Kobra for a second time, he easily dispatched Shimmer with bolas.
Shimmer lead a team of Kobra cultists to steal a cobra dagger from the Star City World History Museum. Green Arrow and Artemis tried to stop her, but their arrows only took down her henchmen. Artemis's oil arrow did contain microbeads with a tracer, which latched on to Shimmer's clothing. She made it to the escape helicopter, and disabled another tracker arrow that Green Arrow had shot.
During the ritual, Batman, Flash, Green Arrow and their protégés interfered. Whilst Mammoth and the other cultists engaged them, Shimmer stood by her master to help him with the completion of the ritual. When it was complete, she tried to take on Robin. She failed to realize he was a distraction, and Artemis shot a bola arrow to bind her. She was knocked to the ground, and watched as the fight went on. Following Kobra's defeat, she was sent to Belle Reve Penitentiary.
Shimmer was working for Queen Bee with Mammoth, Psimon, Icicle Jr. and Devastation. She helped rounding up runaways and strays from all over the world to send to the Partner. Soon after they arrived in their main base of operations, intruders were spotted. After the capture of Batgirl, Psimon sent Shimmer to make preparations for the transport of the abductees. Miss Martian found her, and took her out with a brain blast and read her mind. She stored Shimmer in an empty oil drum.
Bialya February 20, post-10:34UTC+2
Mammoth had taken his sister out of the drum, but she was still unconscious when Queen Bee checked on the damage in person.
Shimmer, still in a pod, was transferred to a Reach ship under the ocean. Along with the other abductees, Shimmer was experimented on, and was later freed by the Team. While en route to the Bio-Ship, they encountered Black Beetle. In the ensuing battle, Shimmer switched sides, and fought against her would-be liberators. However, she was defeated by Batgirl.
Still groggy, Shimmer's metapowers activated, and she inadvertently dissolved a section of the hull. A rush of water slammed into the room, knocking Shimmer unconscious and breaking up the battle between the two Beetles. Black Beetle saved Shimmer from drowning, but was forced to let Jaime Reyes escape.
Bialya June 14, 05:19UTC+2
Shimmer, Mammoth and Devastation made a show of defending the Bialyan temple base against a joint Team-League incursion. A combination of Batgirl's martial arts and Zatanna's magic sent them all through a hole in the floor created by Shimmer.