But the Red Eye didn't report the presence of any Gems on this planet!
|—Peridot "Marble Madness"|
Red Eyes are meteor-like devices created by Homeworld. One was sent to Earth and monitored by Peridot in "Laser Light Cannon" to see if any Gems lived on the planet, but was destroyed by the Crystal Gems. In "Gem Heist", a Red Eye is seen hovering outside of Pink Diamond's Zoo.
Red Eyes, as their name entails, are massive, red-orange, eye-like device. As such, it is spherical in shape. The Red Eye has a light orange hexagonal iris with a red-orange, aperture-like "pupil" of the same shape. Its body (or sclera) is orange and is covered by a cream colored segmented covering (or eyelid) that can close and open to protect the eye. It seems to have the same triangular patterns that are shown on the floor of the Gem Warship, meaning that it belongs to the Gem Homeworld. This is confirmed when Peridot states that its purpose was to scout out other Gems on Earth. It seems to be constantly emitting light, or in some cases glowing.
By using some anti-gravity drive, it can defy Earth's gravitational pull, freely levitating over the surface. It is also highly durable, having a very hard body which provides exceptional defense against physical attackers, as seen when it withstood multiple attacks from Amethyst and Garnet without taking any damage, only taking major damage from Rose Quartz's laser light cannon. The aperture-like pupil/iris can open up and create a powerful gravity anomaly, capable of attracting nearby objects of significant mass.
It threatens Beach City with its potential of colliding with the Earth, which would likely kill all of Beach City's residents. Garnet, Amethyst, and Pearl try multiple times to stop it by throwing Amethyst at it, but find no success in doing so. It is implied that it cannot be destroyed without Rose Quartz's Laser Light Cannon, which Steven finds. He and the Gems use it to destroy the Red Eye, causing it to explode violently.
Fragments of the Red Eye are seen on the boardwalk.
Peridot revealed that the Red Eye was a scout sent to Earth by Gems, presumably to ascertain as to whether or not there were Gems present on Earth. Peridot says that she is there with only Jasper under the belief that there were none, due to it not sending back a positive report. She is shocked that she (or the people who assigned her) was acting on null (missing) data.
A Red Eye is seen next to Pink Diamond's Zoo.
- The initial diameter of Red Eye is about 16-20 feet, which could be easily determined by comparison with Amethyst's size (4-5 feet) in the moments of impact. In later scenes, it appears to be significantly larger.
- The Red Eye functions very similarly to the moon from The Legend of Zelda: Majora's Mask, where the moon is crashing down to the planet, and there is a limited time to stop it.
- The Red Eye is similar to Ramiel or Leliel, Angels from Neon Genesis Evangelion. It is spherical like Leliel and geometric like Ramiel, and shares both Angels' trait of being a large, slowly-floating object.
- It also resembles the angel Sahaquiel, both of them resembling giant eyes that are falling towards Earth.
- Ian Jones-Quartey, creative director of the show, stated on his blog that the Red Eye is not a Gem.
- The Red Eye's "iris" resembles a Rupee from The Legend of Zelda series.
- Since the Crystal Gems knew what the Red Eye was without knowing about advanced Homeworld technology, it can be assumed that the Red Eye is an Era 1 device.