This article contains information that is considered canon in the "Steven Universe" universe.
Nephrite, also known as the "Centipeetle Mother", Centipeetle or Centi in her corrupted state is a Corrupted Gem that debuted in "Gem Glow". Before her corruption, she was the captain of a squadron that was sent to Earth 5,750 years ago in a ship to colonize Earth, and later was trapped on Earth during the Rebellion. She currently resides in her old ship after being reunited with her crew mates in "Monster Reunion".
Nephrite's corrupted form is that of a giant centipede-like creature. She is composed of roughly thirteen (visible) dark-green segments (excluding the head and the rear) that each bear one pair of similarly colored legs. The final segment bears no legs, but what appears to be a pair of mandibles. Each of these segments is covered on the top side with a hard crystal covering. Her head is composed primarily of a gigantic pair of jaws/mandibles with a gem in the back of the "mouth". This gem is circular in shape and colored light green with dark-green contour lines surrounding the circumference of the gem, connecting to a circular shape. Her gem seems to act as its iris, being in the middle of what would rationally be a sclera. It also features a green crystal protuberance on the base of the head that forms a broken horn-like structure. She has a flowing, light-cream colored mane immediately behind her head.
After being released from the bubble in "Monster Buddies" and regenerating, she appears in an all-around reduced form. Her body is reduced to only two segments, and its mane, head, and secondary mandibles have been reduced in size as well probably indicating that she has to grow over time. This can be seen as the Centipeetle Mother grows throughout the episode. Her gem now comprises the entirety of its whole eyeball instead of just the iris, and the gem on her head is now gone.
While her mind is still damaged by the diamonds, her form takes on a more humanoid appearance thanks to Steven's healing. Her body appears more humanoid, and her head is slightly different than her fully corrupted form, her eye is no longer inside of her mouth. She also has what appears to be a sort of pincer on her rear. She wore torn-up light gray clothing, and what appears to be a bodysuit similar to Pearl's in Space Race.
Nephrite and her squadron were ordered to travel to Earth on an Ancient Gem Colony Ship with the plans of colonizing the planet. Once the Rebellion had begun, Nephrite and her crew fought in the war, but Nephrite eventually got split up and was on her own. A unknown Hessonite, Nephrite's commander, ordered all the Gems to retreat either through the ships or warp pads, but she had been left behind, unable to escape. She was then corrupted, along with nearly every other Gem that remained on Earth, by a weapon activated by the diamonds.
In "Gem Glow", Nephrite attacks the Temple along with a bunch of little Centipeetles that she summons. Once the infestation appears to be over, Nephrite returns, and Steven, in order to prove himself worthy, and to protect his loved ones, throws his Cookie Cat refrigerator at Nephrite, electrocuting her, and Nephrite is poofed and bubbled.
In "Monster Buddies", Steven accidentally pops Nephrite's bubble and she transforms into a smaller, less menacing version of herself. When the other Gems come to protect Steven from the apparent threat, Steven defends Nephrite, and the Gems let him try to train her. Steven eats Chaaaaps, which attracts the Nephrite, and Nephrites displays enjoyment for Chaaaaps. When a seagull comes to try and take the chips away, Nephrite comes to Steven's rescue and attacks it. Later, Garnet explains that Nephrite could be used on a mission to retrieve the Shooting Star. Traveling through the ice caves, Nephrite easily uses her corrosive liquid to erode the cave walls and get to the Shooting Star. When the cave is about to collapse, Nephrite pushes Steven out of the way of a falling icicle and sacrifices herself. She is bubbled once more.
In "Monster Reunion", Steven's healing spit is back and he convinces the Gems to let him try and heal Nephrite with his power. He does so, but Nephrite transforms into a semi-corrupt form, gaining humanoid arms and legs but the inability to speak properly. Steven convinces the Gems to let Centipeetle stay, and later, Nephrite and Steven communicate through art. Nephrite tells Steven her backstory, and then begins to revert into her corrupted form. Steven tries to heal her again, but to no avail. Nephrite tries to use the warp pad but cannot, so she reveals to Steven that she wants to go to her ship. Steven takes her there, and on the way, Nephrite reverts back to her corrupted form completely. Inside the ship are other Centipeetles that look exactly like herself, and it is revealed through Nephrite's writing (which is in the Gem language) that it was her crew members that were waiting for her to return home. Nephrite is currently living inside of the ship with her crew.
Nephrite is capable of eating with her mouth despite her eye being located in her jaw and blocking her throat, thus making it so that there is no visible means of having the ingested food reach any sort of stomach.
- Hybrid Arthropod Physiology: Due to having the appearance of two arthropods, specifically a centipede and a beetle, Nephrite has the innate abilities of both organisms.
- Chilopodan Physiology: Like a centipede, Nephrite uses her jaws to attack enemies or prey. Both employ deadly substances in their attacks. The centipede uses venom while the Mother uses a corrosive liquid.
- Coleopteran Physiology: Like a beetle, Nephrite's defenses are increased due to the hard gem-like covering each segment possesses.
- Climbing Skills: She is able to climb vertical walls and sheer cliff faces.
- Creature Creation: Nephrite has the ability to produce and command Centipeetles that aid her in battle.
- Corrosive Liquid Generation: She can produce an extremely corrosive substance that can easily erode various materials, ranging from wood to stone to ice. She can use this corrosive substance as a projectile to attack from afar or assault enemies with a constant torrent of the substance to easily break down their defenses.
- Rotative Spitting: In "Monster Buddies", the small corrupted version of Nephrite is seen to be able to rotate its head many times. She utilized this in that she spun her head rapidly and sprayed its corrosive substance, showering the immediate area in a manner extremely similar to that of a sprinkler.
This isn't you! You're not a monster anymore! You're more than that.
After being healed by Steven, Nephrite, at first, does not appear to remember him. However, after Steven opens a bag of Chaaaaps, her memories begin to return and she starts remembering him, and her memories of before she was corrupted. Nephrite appears to have been very friendly towards Steven, even after reverting to her fully corrupted form.
- When Nephrite was reforming herself after she escaped from the bubble, she briefly took a humanoid form before taking her latest form.
- It was revealed in "Ocean Gem" that Nephrite, along with most of the monsters previously fought, used to be humanoid Gems. Unfortunately, the Gems became corrupted, turning them into the monsters they are now.
- Nephrite is the first corrupted Gem to be shown and the first that Steven defeats. She is also the first to be released from its bubble, be (temporarily) healed and to display some level of higher intelligence.
- Her gemstone bears resemblance to a PokéBall from the popular Nintendo series, Pokémon.
- Her name is a portmanteau of the words centipede and beetle.
- When semi-corrupted, her gemstone's design slightly differs than when she is corrupted.
- Nephrite serves as the antagonist of the iOS game, Crystal Gem Smash.
- Nephrite is the only Corrupted Gem so far to ever reform onscreen.
- Nephrite's white messy hair in her corrupted and semi-corrupted state is similar to those of Jasper and Amethyst.
- As shown in "Monster Reunion", Nephrite is fluent in the Gem language.
- Nephrite's semi-corrupted form bares resemblance to the villain "Zorak" from the Space Ghost metaseries.
- Nephrite, although unable to communicate properly through speech, was able to legibly state where her crew was in the Gem language.
- In "Legs From Here to Homeworld", it is revealed her gemstone is a nephrite.