The "Laser Light Cannon" is a powerful magical cannon that was once owned by Rose Quartz. It is the titular object of the first episode it appears in, "Laser Light Cannon",in which it was used to destroy the Red Eye,and seen in "Rose's Armory" and then is seen again in "The Return", in which it was used in conjunction with the Quartizine Trio in an unsuccessful attempt to destroy the incoming Gem Warship.
The Laser Light Cannon is a large, light pink, cannon-type magical weapon made up of a crystalline material. It is bulky, extremely heavy, and is implied to be considerably durable. The barrel, backside, and hinges of the cannon all follow a floral motif, which is reflective of the cannon's original owner, Rose Quartz.
The cannon seems to have a process of activation that resembles the blooming of a rose. The inactive form of the Laser Light cannon has an appearance similar to a developing rose bud. Once the key phrase is stated, the cannon glows as it charges in preparation for firing. In the active form, the muzzle of the cannon appears to bloom like a fully developed rose then fires its volley. The cannon fires intense beams of peachy-pink light which morph in the air to take the vague shape of Rose Quartz. The cannon does not require any sort of ammunition. There is no visible firing mechanism, although it appears to be activated by Greg's phrase "If every pork chop were perfect, we wouldn't have hot dogs." The beam is immensely powerful and is identified as the only thing (on Earth) strong enough to destroy the Red Eye. Additionally, when it is used alongside the Quartizine Trio, three additional laser light cannons, the multiple beams become synchronized and appear to twirl around each other presumably amplifying the strength of combined beam. Despite this, the light cannons were not able to penetrate the more modern technology of the gem hand ship.
The history of the cannon prior to the events of "Laser Light Cannon" is, for the most part, unknown. This includes its creation and its previous usage, though it may have been used by the Crystal Gems during their rebellion against the Gem Homeworld.
When Beach City is threatened by the nearing Red Eye, Garnet tells Steven that Rose's light cannon is the only thing powerful enough to destroy it. However, the Gems had lost track of it in the time since Rose gave up her physical form to give birth to Steven. Steven tracks down the cannon, locating it in his father's storage unit. Steven retrieves the cannon and, with the help of his father, returns it to the waiting gems just as the situation becomes increasingly dire, as the gravitational pull from the approaching Red Eye continues to grow stronger. The Gems struggle to activate the cannon, until Steven remembers his father's often repeated aphorism "If every pork chop were perfect, we wouldn't have hot dogs." This quote, when spoken aloud, is what ends up activating the cannon. After a brief period of setup, the cannon fires upon and successfully destroys the Earth-bound Red Eye. Later, in "The Return", it was used alongside the Quartizine Trio in an attempt to destroy the Gem Warship, but the beams were dispersed harmlessly against the warship's palm.
- The back end of the cannon features a design that strongly resembles Steven's shield weapon.
- When Greg says his catchphrase "If every pork chop were perfect, we wouldn't have hot dogs!" outside of the storage unit containing the cannon, the cannon gives off a slight pink glow, foreshadowing how it would later be activated. This glow is also how Steven was originally able to locate it.
- This also happens while the cannon is being driven to the Crystal Gems; Greg repeats the phrase, and the cannon, sitting in the back of the vehicle, glows slightly.
- When the cannon is activated, it turns into a form similar to a rose, and the laser is shaped like a silhouette that looks similar to Rose Quartz.
- Rose's Quartizine Trio has three cannon-type weapons which strongly resembles the singular Laser Light Cannon.
- The Cannon has only been shown twice, only in Season 1.