Some TMNT stuff really isn't for little kids.
Lindsey developed the psychotropic compound, part of her "Splinter Project" that divided human like cognition from animal instincts, Splinter being the first test subject given the drug. The experiments on Slash at StockGen, hoping it would validate her theories about mutation. When the Foot Clan attacked the lab, the compound and Splinter were lost, leaving Slash without the drug's mind enhancing elements needed to keep his primal instincts in check. His rampages caused great damage, and Baxter Stockman shelved the project, using her as a scapegoat.
After Old Hoband Slash destroyed StockGen, she had a hard time finding work, as few companies were performing experiments similar to StockGen and her references seemed to have vanished. Hob and Slash kidnapped her at gunpoint outside her house, then tied her to a chair, offering her a table full of money to help them make a mutant army to protect the other mutants of New York. Hob had obtained a large canister of ooze and samples of Splinter's blood (containing the missing psychotropic compound). Slash willingly injected himself with some of Splinter's blood, and the compound within it made Slash intelligent in moments, proving her theory correct. She then used a gecko and hermit crab stolen by Hob and Slash to create Mondo Gecko and Herman the Hermit Crab, having successfully combined the compound with the mutagen. Then she and Old Hob mutated a pigeon who was then named Pigeon Pete.
Lindsey and Pigeon Pete were kidnapped by the Null Corporation, where Lindsey was offered a job by her former girlfriend Jillian Amante. When Hob and the Mutanimals arrived and began causing havoc, destroying the lab, she seemed to conclude it might be better to team up with Jillian and follows her out as the lab is wrecked.
She and Jillian met with Null, who essentially forced her to agree to work for her. Realizing Null is evil, she returned to the Mutanimals, saving Mutagen Man Seymour Gutz when he was planning a suicide attack. Hob agreed that she was still needed for her skills with mutagen and shared dinner with them.
She became a permanent member of the Mutanimals crew, becoming fond of the idiosyncratic group while remaining neutral about Hob's sometimes morally-ambiguous ways. When the Mutanimals were captured by the Earth Protection Force, Lindsey was captured with them, and was permitted to advise them on the medical treatment of the critically-injured Seymour. She was later freed with the rest of the Mutanimals after Hob took hostages.
She took care of Seymour in the weeks that followed, watching television with him every night to keep him company. When his condition began to decline, she was only able to put him in a coma, since they were without the equipment necessary to build him a new body. After Mondo and Michelangelo successfully brought her the equipment, she was able to rebuild Seymour's body, saving his life.
- Lindsey Baker along with her ex-girlfriend Jillian are some of the first confirmed LGBT characters in any official TMNT universe that are recurring characters and not merely bit characters. They are also the first human non-bit characters that have been confirmed to be LGBT, but they are not the first non-human LGBT non-bit characters. Soowiiksa/E'ro'chk, who was first introduced in Teenage Mutant Ninja Turtles Volume 4 Issue 32 (February 2006), was revealed to be lesbian in Issue 32 (May 2014). Lindsey was not confirmed to be lesbian until 2015.