Cy-Bugs

"Cy-Bugs are like a virus. They don't know they're in a game. All they know is eat, kill, multiply! Without a beacon to stop them, they'll consume Sugar Rush! But do you think they'll stop there?" "Yes!" "WRONG! Viruses do not stop! Once those Cy-bugs finish off Sugar Rush, they'll invade every other game until this arcade is nothin but a smoking husk of forgotten dreams."

- Sergeant Calhoun explaining Cy-Bugs to Fix-It Felix, Jr.

The Cy-Bugs are a race of robotic bug-like creatures and are the secondary antagonists in the Disney animated film Wreck-It Ralph. They serve as the generic enemies in the mythical game Hero's Duty. Because of some of the failed programming of Hero's Duty, Cy-Bugs are unable to tell the difference between the game and real life, meaning they are truly malevolent creatures unlike other characters who are merely villains in their games only. This forces the heroes of Hero's Duty to constantly battle the bugs to prevent them from destroying the entire arcade. The Cy-Bugs are not only intimidating in appearance, they are also very powerful.

Background
The Cy-Bugs, as their name suggests, are robotic creatures resembling insects, most notably a silverfish. Like insects, they are instinctive and only have three motives: kill, eat, and reproduce. They attack in swarms and devour anything in their path, making them even more destructive. Because they were designed to be primitive and bestial, they are non-sentient and dangerous beings in both game and reality as opposed to villains who are simply evil in their game. This effectively makes them viruses if released in the game world. In their game, their eggs are kept at the tower for every new game that starts, as they are native to the program and cannot be removed. Hatchlings are quite vicious like the adults and grow at a rapid rate. A single Cy-Bug can lay hundreds of eggs given it has proper conditions to survive and sustain them. The most notable, and deadly, ability the Cy-Bugs contain is turning into anything they eat, be it organic or inorganic. The results can range from simply changing parts of themselves into weapons (etc. when one ate Ralph's gun and turned his appendages into the same kind) to a completely different form of the original (etc. when many ate the contents of Sugar Rush, turning their carapaces into lookalikes of candy, cakes, and chocolate). Devouring video game characters inside their game doesn't seem to change them (etc. Calhoun's husband to be). Ones outside of their games, however, causes them to transform into a horrific fusion of the character and the bug, and the character seems to become the dominant personality (albeit, more psychotic and sinister), while retaining the Cy-bugs' basic instincts (etc. King Candy).

Though they are mighty opponents, the Cy-Bugs do have weaknesses. Laser guns from Hero's Duty and other weapons can destroy Cy-Bugs as long as the guns aren't eaten, otherwise the Cy-Bugs can use their own foe's weapon against them. Their greatest weakness is their attraction to immense rays of light, similar to a real bug's attraction to a bugzapper. Once they sense a form of light, the Cy-bugs cannot stop themselves from heading towards it, even if it is lethal. As a result, a special beacon has been built into the tower that attracts and destroys them between games.

Wreck-It Ralph
The Cy-Bugs first appear in the 1st-person shooter game, Hero's Duty, preparing to attack a fleet of soldiers. When Ralph interfered with the game, one of them came close to nearly killing Ralph and the player. This forced the soldiers to end the game early and stopped the swarm by launching the tower's beacon of light, immediately attracting the Cy-Bugs and killing the swarm. Later, Ralph climbed to the top of the tower to achieve the gold medal and accidentally hatched one of the eggs at the top. The hatchling clung to Ralph, causing him to become disorientated and fall into an escape pod. The two were launched out of the tower into Game Central Station and then into Sugar Rush. The hatchling quickly grew and ate away some of the escape pod and proceeded to attack Ralph, however Ralph then flung it into a pond of extremely sticky taffy, where the Cy-Bug seemingly drowned.

It is revealed, however, that the Cy-Bug survived and burrowed its way underground. It found a candy root and tried to eat it, and transforms into a colorful candy hybrid as a result. Sergeant Calhoun later discovers its massive nest, where the Cy-Bug had quickly reproduced, multiplied, and created more candy-bug hybrids by feeding its offspring with the indigenous sweets of the land.

The creatures make their move when the race begins, and destroy everything in site. The attack enforces the evacuation of the Sugar Rush residents, but leaves the racers Vanellope von Schweetz and King Candy in danger. Vanellope escapes from him and races ahead, but King Candy gets swallowed by one and ends up taking control of it, turning into a viral hybrid monster, and becomes the Cy-Bugs' leader. Ralph overhears Calhoun explaining to Felix that the bugs cannot be stopped without a beacon and comes up with an idea to erupt the Diet Cola Mountain to produce another beacon of light. Though the King Candy monster tries to kill him, Ralph breaks free from the King and brings down an entire crater of mentos into the lava, causing the mountain to erupt. The eruption produces the beacon, and the Cy-Bugs who have been closing in on Calhoun, Felix and Vanellope (who glitches past the bugs to go to Ralph's rescue) stop their advances, turn to the beacon, fly toward the light and get vaporized along with King Candy, killing them.

Trivia

 * The Cy-Bugs' power to assimilate anything they eat into their physical structure is probably a joke on the saying "You are what you eat".
 * The Cy-Bugs' power also is a reference to video game star Kirby who also gains the powers of a foe he's eaten.
 * Although King Candy crowns himself the leader of the Cy-Bugs after being eaten by one by accident, the Cy-Bug queen, the implied final boss of Hero's Duty and the Cy-Bugs' true leader does not appear until the events of Wreck-it Ralph: The Video Game as the main villain.
 * Cy-Bugs could be based on Metroids, the main enemy from the video game series of the same name. This is supported by the fact that, in their early stages, they seem to feed off of other beings, and then become stronger.
 * It's implied that the Cy-Bug that ate King Candy/Turbo during the climax is actually the same one that Ralph accidentally brought into Sugar Rush while escaping from Hero's Duty since it stowed away in the escape pod Ralph was in. If this is true, then this is most likely the reason why Turbo becomes the Cy-Bugs' leader, as they would naturally follow the one that hatched them, and if the Cy-Bug that ate Turbo is indeed the same one that Ralph set loose which hatched them, than the Cy-Bugs would believe that Turbo is the one who hatched them.
 * Another hint is that when Turbo confronts Ralph in his Cy-Bug form, Turbo says he became one because of Ralph, suggesting he knew that Ralph was the one that brought the Cy-Bug into Sugar Rush, even though he never saw Ralph enter the game, meaning he gained the original Cy-Bug's memories.
 * According to the opening cutscene of Hero's Duty, Cy-Bugs were the result of "an experiment gone wrong."
 * They are domestic in a way because the game, Hero's Duty, is owned by Mr. Litwak even though he dosen't know the secret of videogames.
 * The Cy-bugs instinct to multiply makes them similar to the Xenomorphs from the Alien franchise. Their ability to absorb the characteristics of their food also parallels the Xenomorphs' ability to absorb the traits of their hosts.

Similarities toward regular bugs

 * The Cy-bugs weakness is light which is very similar to that of flies' weakness toward bugzappers.
 * Interestingly, the Cy-bugs' love of sweets when they came to Sugar Rush is a similar to how bugs such as ants or flies love human food.
 * They also appear to love in groups as well.
 * They are hated by all of the rest of the characters in Wreck-It Ralph.