|Base of Operations||Arkham City (formerly)|
|Affiliations||The Joker (formerly; Mr. Hammer only)|
|Hair||Green (Mr. Hammer)|
|Eyes||Blue (Mr. Hammer)
|Height||6'10" (Mr. Hammer)
|Weight||290 pounds (Mr. Hammer)
300 pounds (Sickle)
|Appeared In||Batman: Arkham City|
|First Appearance||Batman: Arkham City|
Before Arkham City Incident
The Abramovici Twins were born in a small Siberian village, and their father, Andrei, was a poor shoe-maker. Their mother died unfortunately during labor, which caused Andrei to resent his conjoined sons. Andrei tried to drown them in a river near the village, but when he saw a wolf-mother playing with her two pups nearby, he remembered his responsibility as a parent, and hindered himself. But Andrei had neither the strength nor the will to raise his sons, so he abandoned them by the doorstep of a local circus. The twins grew up as part of a freak show, but no one knew about their monstrous strength until they killed a tiger that attacked the audience. They soon received the nicknames "Hammer and Sickle" because of their individual weapons. The Joker heard about them and tried to recruit them for his gang. When the circus-owner refused to sell them, Joker killed him with his Joker Toxin and transported the twins to Gotham City.
Arkham City Incident
After he set up his base of operations at the Steel Mill in Arkham City, Joker realized that the twin's conjoinment hindered them during battle, so he hired Hush to surgically separate them. After not thinking that he needed more than one giant-sized henchman, Joker ordered Harley Quinn to get rid of Sickle. Later, Penguin found a one-armed man dumped outside his doorstep with a note that mockingly said "wingless bird". Sickle was brought in and recruited as a member of Penguin's Gang.
After Joker's defeat and death, the twins could be found in the Steel Mill at the Assembly Line sitting together in a secluded room. The twins addressed how they never should have parted ways to begin with, decided to work together again, and believed themselves to be unstoppable as a duo.
Before Arkham Knight Incident
Both of the Abramovici Twins were sewn back together and Sickle's mouth stuffed with straw by Scarecrow to send Penguin a message.