Cydney "Cyd" Phyllis Ripley is one of the main protagonists in Best Friends Whenever. Cyd is Shelby Marcus's best friend, and the two girls live together in Shelby's house due to Cyd's parents leaving for Peru, and eventually dying. Cyd and Shelby discover the power to time travel together by messing around with a science machine. Cyd is a tomboyish, gluttonous, rebellious, and aggressive young teen. She likes getting into trouble, and often gets Shelby and herself into tricky situations.
Cyd is portrayed by Landry Bender who also voices Makini.
Cyd is a tomboy who is very sarcastic. She likes to eat a lot, and can be very lazy. Cyd is a big troublemaker, and often acts without thinking. Cyd generally doesn't think things through, but its more out of laziness and impulsiveness than any genuine stupidity. Though she can be slightly slow on the upkeep. Cyd is a bit more cynical, and also a bit blunt. Not touched upon often, but Cyd's pretty childish. When she goes back to Kindergarten she practically has the time of her life.
Underneath her tough girl personality, Cyd has occasionally shown signs of insecurity, such as feeling like she didn't fit in with Shelby's family, and feeling guilty due to them all being so nice to her. Shelby later fixes this, and boosts Cyd's confidence. However she has other insecurities, such as being afraid of growing up.
Cyd is the kind of person who is willing to make any sacrifice for her friends, especially Shelby. This is shown when she forced Janet into taking her inside Janet's machine first instead of Shelby, despite knowing it would kill her.
Cyd has straight dark brown hair with brown eyes. She would wear very stylish shoes with long socks and tops with the pants not being that big in the style of each outfit. Cyd's style is edgy which goes along with her personality. She would always wear a jacket with her outfit with a t-shirt being underneath. Sometimes Cyd would wear overalls. Her style is effortless but shows the tomboy vibe and her fun side.
Shelby and Cyd have known each other since kindergarten and have experienced many things on their way. Although the two girls are best friends and do everything together, they are exact opposites. After an experiment gone terribly wrong, the two girls use the power to time travel "whenever" they want.
Naldo and Cyd are close friends. Cyd sometimes thinks that Naldo is silly and weird, but is close friends with him. In When Shelby Met Cyd, Shelby reveals that Cyd went through a phase where she had a crush on Naldo in 4th grade, which would explain why she always punched and shushed him back then
Barry and Cyd are close friends. Cyd doesn't enjoy learning about science, and tries to avoid Barry talking about it. However, she often come to him when she has problems.
Time Travelling - Cyd & Shelby have a time travel power which makes them move to the past and future by touching each other in any way. This is a special power that no one has ever discovered.
Tachyon Rays - Being infused with Tachyon particles, Cyd and Shelby also have the power to blast Tachyon Rays, as shown in their battle against Janet in Fight The Future, Part 3. They can also use this power to take away other people's tachyon particles.
Boxing - Cyd has a punching bag in her room and loves to box. She also punches both items and people in the show which makes for funny moments.