Eyeball Ruby

"Oh, give it up already! You can't take this away from me! I'm gonna be a legend! I'll go down in history! What will the Diamonds say when they hear that a ruby defeated Rose Quartz? They're gonna give me my own pearl!"

- Ruby (aka Eyeball) while trying to shatter Steven.

Ruby-1F4 Cut-4ND, or just Ruby or Eyeball (to Steven) is a Homeworld Gem and the final antagonist of the third season of Steven Universe. She made her debut at the end of "Barn Mates" and her appearance in the season 3 finale, "Bubbled", where she served as that episode's main antagonist. She later returned in the Season five episode "The Trial" where she is revealed to have returned to The Gem Homeworld somehow.

Overall, Eyeball and the rest of the Ruby Squad serve as the secondary antagonists of Season 3.

She is voiced by Charlyne Yi.

Appearance
She has Scarlet skin, the lightest out of all the rubies. Her assemble includes a maroon Homeworld uniform and burgundy shorts. She has big, thick dark burgundy hair and her gem placement replaces her left eye, giving her the nickname Eyeball by Steven.

Personality
Eyeball Ruby seems to be the most invested in the mission to track Jasper and is well-informed about her. She is stoic, rarely speaking before "Back to the Moon", though occasionally appearing to be trepidatious and anxious. She appears to be intimidating and treacherous, but is also quite appreciative and polite when thanking the Crystal Gems for their cooperation. Despite her tough exterior, upon meeting her hero Jasper (really a disguised Amethyst) she was struck with awe and showed an almost fangirl-like zeal.

Like the other Rubies, Eyeball is very insensitive and obtuse in recognizing trickery, being easily fooled by disguises or lies. However, she is the only one to be naturally suspicious of Ruby when Ruby kept interacting friendly with Sapphire during their baseball game, eyeing them with an uncomfortable expression. Humorously, she also suspected Leggy, watching her when she was cheerfully standing next to Lapis Lazuli.

Even over her own captain, she is the most experienced in Gem history, the only one to remember the location of the diamond base on the moon and explaining the history of the moon base and Pink Diamond. This is partially due to being the oldest of the Rubies and having fought in the war.

She also seems to be quite insecure about her relationships, as shown when Ruby and Sapphire were talking to each other in Hit The Diamond. As they chatted, Eyeball watched them with a sad look on her face. Another example was when Amethyst as Jasper placed Doc onto her lap when they were heading to the Moon Base, which caused Eyeball to cry.

Pre-Series
5,750 years ago, Ruby 1F4 Cut-4ND fought for Homeworld during the war for Earth. During this time she witnessed Rose Quartz shatter Pink Diamond.

Barn Mates
Eyeball is seen for the first time peeking out of the Roaming Eye, after it is crashed by Lapis Lazuli, shocking the Gems.

Hit the Diamond
Eyeball and the other Rubies descend upon Earth looking for Jasper. Upon discovering the barn, they are tricked by Ruby and Steven into believing that only humans live there. They are then told that they can only search the barn if they beat the 'humans' at baseball. After learning the 'humans' were, in fact, the Crystal Gems, Eyeball, along with the other members of her squad, fuse together and demand to know where Jasper is. Upon being falsely told by Steven that Jasper was on Neptune, they defuse, and Eyeball thanks him.

Back to the Moon
The rubies return to the barn, incredibly irate for being tricked about Jasper's location. When questioned by the Crystal Gems, Eyeball refuses to reveal any information. After much badgering about the subject, Amethyst shape-shifts into Jasper's appearance, which deceives the Rubies. It is Eyeball who first greets 'Jasper', sharing her serial number as well as that she originally fought in the war on Earth. She was also revealed to be a long time admirer of Jasper's military accomplishments. On the Rubies' ship, while Amethyst as Jasper talks to Doc, another Ruby, Eyeball is visibly jealous. She believed the Gems' ruse all the way up until the Rubies' departure from the moon base, even feeling flattered that Amethyst-Jasper gave her an important mission, but ultimately Eyeball and the other Rubies saw Amethyst undisguised. The Rubies fused in an attempt to attack the Gems, but were almost instantly dispatched when Sardonyx knocked them out the airlock, opened by Steven. Before flying away, Eyeball pulls Steven out the airlock with her into the vacuum of space.

Bubbled
Eyeball manages to hang on to Steven's bubble as they drift through space. After a heated argument, Eyeball tells Steven that she initially could not believe that the Crystal Gems still existed, but grew to realize that it was true if the situation included Jasper and Rose Quartz. Steven tries to explain to Eyeball that he was the offspring of Rose and that he inherited her gemstone, showing her his gem and his shield, but Eyeball does not believe him. They drift into an asteroid field, which results in the cracking of Eyeball's gemstone. Steven pulls her inside of his bubble and heals her, causing Eyeball to believe he was Rose after all. Eyeball then attacks Steven, because Rose had betrayed Homeworld and shattered Pink Diamond. Eyeball states that she hopes to be rewarded back on Homeworld, possibly with her own Pearl. This forces Steven to eject her from his bubble and send Eyeball spinning through space.

Mindful Education
While training at the Sky Arena, Stevonnie experiences a large hallucination of Eyeball, with Steven expressing guilt from being forced to fight her and leaving her in space.

Room for Ruby
Garnet initially thought that Navy was Eyeball, and tells Steven not to trust her because she tried to stab him in space, before Steven corrects her.

The Trial
Eyeball makes it back to Homeworld through unknown means after floating through space for so long (likely picked up by Navy who got their ship back). She tells the Diamonds what she knows about Rose Quartz (Steven), and appears as a witness during the trial. At the trial, Eyeball tells the court how Steven said he had Rose's shield and all of her other powers, making Steven appear more guilty.

Abilities
Like most other Gems, Eyeball can change shape, invoke a weapon, take refuge in her gemstone to heal, and adapt to any extraterrestrial environment's gravity. She can also fuse with her fellow Rubies to form a larger Ruby. She presumably has the standard abilities of a Ruby, such as thermokinesis, pyrokinetic touch, and heat resistance.


 * Chisel Knife Proficiency: In "Bubbled", Eyeball is seen to have a chisel knife as a weapon.
 * Photokinesis: In "Back to the Moon", She is shown projecting a red light from her gem. She shares this ability with Pearl, Garnet, Peridot, and Doc.

Fusions

 * When fused with multiple Rubies, specifically "Doc", "Army", "Navy", and "Leggy", they form a larger Ruby.

Quotes
"I’m not telling ya’ll nothing about nothing!"

- Eyeball to the Crystal Gems.

"I'm Ruby-1F4 Cut-4ND. I fought in the war for Earth."

- Eyeball

Trivia

 * Eyeball is the first non-diamond gem antagonist on the show to not of been poofed on-screen.
 * She gained her nickname "Eyeball" from Steven based on her gem positioning, that being on her left eye.
 * She is the first antagonist gem to become a villain in a later episode, rather than her debut.
 * Eyeball is the oldest of the five-Ruby squad, dating back to the rebellion. She even fought in the Gem War.
 * Like Jasper, Eyeball may had been a underling of Pink Diamond, as it is revealed that she witnessed Pink Diamond's death by Rose Quartz.