- Oh, dear, not slavers! Why, that's almost nearly the sort of kind of barely a little bit about half as bad as the murderders and despots we normally work for!
- — Rag Doll src
Given that his father was a sociopath and a cult leader, his was probably not the most conventional of upbringings. He indicates that his father was abusive due to disappointment at his not being born double-jointed. He has a sister, an extremely brutal (and insane) crime lord who goes by the name Junior. It appears that their relationship was incestuous. Somewhere in his teens he had his genitalia surgically removed. At some point he began thinking about having his bones altered to mimic double-jointedness.
When Peter reached adulthood, he began having his joints replaced one by one with fully-rotating, self-lubricating prosthetics. After twelve years and hundreds of surgeries, he achieved a level of flexibility that his father could only dream about. Needless to say, the original Ragdoll didn't like the competition.
Through unknown circumstances, Rag Doll joined the Secret Six, and helped them throughout a variety of adventures. His role in the Six is that of the demented smart-ass and is constantly trying to prove he is the weirdest and funniest of the bunch.
As part of the team, he joined Bane and Catman on a mission to stop criminals in Gotham after Batman's death. Ragdoll disguised himself as Robin and served as a sidekick to his teammates, but in the end, they were all banished from Gotham by Nightwing. Ragdoll stopped wearing his Robin costume and he also remarked how unsuitable Bane and Catman were for the role of Batman.
During Blackest Night, Rag Doll, the rest of the Six, and the Suicide Squad fought a group of Black Lanterns that attacked them at Belle Reeve's prison. The fight was one of brutality against brutality as the Six repeatedly killed their enemies only to have them continue fighting.
- Contortionism: Merkel is inhumanly flexible due to several joint-replacing surgeries over the years.
- Mental Illness: Ragdoll is very proud of being considered the weirdest and most demented member of the Six, to the point of resenting anyone who might prove to be more demented. This led him to attempt to kill former teammates Mad Hatter and Harley Quinn.
- Power Instability: He requires a special medicine to keep his joints from literally ripping through his skin and tearing his flesh apart. This weakness was exploited by Mockingbird to press gang him into the Secret Six.
- Ragdoll has adopted several little monkeys, each one outfitted with a replica of one of his teammates' costumes.
- Ragdoll is non-binary and uses both he/she pronouns interchangeably. However, he tends to use male pronouns most of the time. 
- 67 Appearances of Peter Merkel, Jr. (New Earth)
- 26 Images featuring Peter Merkel, Jr. (New Earth)
- 9 Quotations by or about Peter Merkel, Jr. (New Earth)
- Character Gallery: Peter Merkel, Jr. (New Earth)