Cree Lincoln is the older sister of Abigail Lincoln. She is currently 16 and is leader of the Teen Ninjas in service of Father. Cree is formerly a KND operative under the codename of Numbuh 11 in Sector V before she turned 13, at which point she escaped decommissioning and defected to the side of evil. It was from Cree that Numbuh 5 learned many of her fighting skills & abilities, but the two are now arch-enemies. She is the quaternary antagonist of the series.
Cree was the mastermind behind such plans as crashing the Kids Next Door Moonbase (a plan she gave up after hearing from Chad that he had already tried it in Operation: E.N.D.), and giving all children the chicken pox while the other teens watched it from the safety of the Pep Rally at her school in Operation: M.A.U.R.I.C.E..
Cree first appeared in Operation: S.U.P.P.O.R.T., in which Numbuh 1 and Numbuh 2 hear that she is wearing a "training bra", which they believe stands for "Battle Ready Armor" and is a weapon being used by adults to train teenagers to become supervillains. Despite the absurdity of this idea, it is proven at the end of the episode to be true. Cree is seen probing her sister's brain (a decoy Numbuh 5) while she sleeps, and meeting up with Father and the Delightful Children From Down The Lane outside.
In Operation: K.I.S.S., Numbuh 2 accidentally turns himself into a teenager and inadvertently encounters Cree. The two fall in love and Numbuh 2 becomes Cree's boyfriend under the name "Hank". During a date, Cree reveals her true nature to her boyfriend and brings him along as she launches a personal attack on the Sector V Treehouse. "Hank" turns on Cree and defeats her, revealing his true identity just as he reverts to his normal self. Cree is shocked upon realizing that she kissed Numbuh 2, and is apprehended and put on a transport to the Moon Base prison. However, as the episode ends, Cree is seen in her bunker contacting "mission control", informing her superiors that she is being taken directly to the Moon Base, to which Father replies that everything is going "according to plan". Ever since this episode, Numbuh 2 has retained a crush on Cree, most notably shown in Operation: S.I.T.T.E.R..
Cree returns in Operation: S.P.A.C.E., when Numbuh 5 and Mushi Sanban encounter her during a resupply mission in space, while the rest of Sector V investigates an abandoned KND prison transport. Cree reveals to Numbuh 5 that it was her plan to be captured all along, and that she intended to escape once she reached the Moon Base. She planned to use the access code she retrieved from her brain to detach the Base from the moon and send it crashing. However, her plan did not go as expected, as during the trip to the Moon, Numbuhs 92 and 93 accidentally pressed the blow up engines button leaving her stranded in space. Cree and Numbuh 5 begin fighting, but Mushi tearfully tells them that, as family, they shouldn't be fighting each other. Cree and Abigail are convinced by the young girl to hug and make up, but Cree is then pushed into the space pod by Numbuh 5 and ejected into space. At the end of the episode, Cree hot-wires the pod to take her directly towards the Moon Base.
At the end of Operation: E.N.D., Cree finally reaches the moon base, only to learn that Chad had just enacted the exact same plot she intended to carry out (and failed). Disappointed, Cree decides to enact "Plan B". Chad, who has been forsaken by the KND and is awaiting decommissioning, asks to join her. She agrees, and the two depart.
Cree is currently the girlfriend of Maurice, formerly Numbuh 9 of the Kids Next Door. However, she is unaware that Maurice is still working for the KND as an undercover agent of TND (Teens Next Door). She went with Maurice to the prom at McClintock High School in Operation: V.I.R.U.S.. Before the prom, she was contaminated by the contagious disease that KND have made in revenge for creating chicken pox which is revealed to be a giant pimple on Cree's cheek. Cree is on the search for the antidote only to have Numbuh 5, who was also infected, retrieve the antidote first and cure herself.
Cree was responsible for scramblifying the brains of several KND operatives when they were injured in Operation: H.O.S.P.I.T.A.L.. As revenge, Numbuh 3 and Numbuh 6 accidentally tricked Numbuh 5's father into thinking that Cree needed surgery.
She last appeared in Operation: T.R.E.A.T.Y.. Although she did not speak much, she was a part of Chad Dickson's group in a message for Numbuh 362, wanting peace. She later appeared at the KND Gihugeacarrier, where she told The Steve "that's no light show." That was her last line in the series, and she made no further appearances in the episode.