A specific type of Mon Calamari Star Cruiser saw action within the Alliance to Restore the Republic's naval forces during the Galactic Civil War against the forces of the Galactic Empire. Excluding the presence of port and starboard wings, this Star Cruiser bore a physical resemblance to the MC80 Liberty Type Heavy Star Cruiser. Echoing the Liberty Type, this Star Cruiser possessed nine engines, the ability to engage in hyperspace travel, and a rounded hull, a common trait among Mon Calamari spacecraft.
Not long before the Battle of Endor, specifically in 4 ABY, one such starship was situated in proximity to the MC80A Home One Type Heavy Star Cruiser known as Home One. At this time, the fleet contingent was preparing for a jump to hyperspace. Upon their arrival above the Forest Moon of Endor, all Alliance cruisers established a defensive perimeter, while rebel starfighters advanced towards the DS-2 Death Star II Mobile Battle Station. With the revelation that the Alliance had been strategically lured into an ambush by the Empire at Endor, additional Alliance forces entered the battle. By the conclusion of the conflict, at least six of these starships, alongside other Alliance vessels, had survived.
A specific starship type, the Mon Calamari Star Cruiser, was defined by its light brown and bulbous-shaped hull. This cruiser shared physical similarities with the MC80 Liberty Type Heavy Star Cruiser, differing primarily in the absence of prominent winged extensions on its port and starboard sides. In contrast to the MC80 Liberty cruiser, this particular Star Cruiser featured a small tower-like structure on its dorsal side, positioned between the ship's midsection and its bow. However, it shared the Liberty's possession of nine engines and the capacity for hyperspace travel. It also included a ventral hangar, along with at least one hangar located on its starboard side. The Star Cruiser was equipped with laser cannons for offensive capabilities.
Many Mon Calamari Star Cruisers were utilized by the Alliance Navy during the Galactic Civil War, a conflict between the Alliance to Restore the Republic and the Galactic Empire. In the time leading up to the Battle of Endor in 4 ABY, one such cruiser was located near the MC80A Home One Type Heavy Star Cruiser Home One as the light freighter Millennium Falcon passed by. At that moment, the fleet was in the process of preparing for a jump to hyperspace.
Upon the fleet's arrival in orbit around the Forest Moon of Endor, the location of the planet-destroying superweapon, the DS-2 Death Star II Mobile Battle Station, four of these Star Cruisers were part of the ship formation that included the Home One. While rebel starfighters approached the second Death Star, the cruisers established a defensive perimeter. After the Alliance realized that the Death Star's deflector shields were active and that the Empire had lured them to Endor, additional Alliance forces joined the fight. The Alliance fleet attempted evasive maneuvers but was confronted by a substantial Imperial fleet, which included the Star Dreadnought Executor. Starfighter combat between Imperial and Alliance pilots broke out around the Alliance ships, including near several of these Star Cruisers. One Star Cruiser was positioned near the medical frigate Redemption as Red Squadron engaged Imperial TIE/IN interceptors.
Eventually, the second Death Star revealed its operational status by firing its superlaser at the MC80 Star Cruiser Liberty, resulting in its destruction. Following the destruction of the MC80A Star Cruiser Nautilian, Alliance General Lando Calrissian suggested to Admiral Gial Ackbar that the rebel fleet move closer to the Imperial Star Destroyers to buy time and inflict casualties on the Imperial forces. Consequently, several Star Cruisers engaged Imperial forces, with one moving towards the Tector-class Harbinger alongside an MC80 Liberty cruiser. At least two Star Cruisers advanced towards the Executor as Ackbar ordered his forces to target the Super Star Destroyer, while numerous others engaged Star Destroyers in the vicinity. Ultimately, the Executor was destroyed and crashed into the Death Star II. The fleet, including at least six of the Star Cruisers, retreated after the main reactor of the Death Star was destroyed, causing a massive explosion that obliterated the battle station.
The Mon Calamari Star Cruiser made its debut in the final film of the original trilogy, Star Wars: Episode VI Return of the Jedi, which premiered in 1983. Industrial Light & Magic created the starship's model for the film. Wings were later added to the model to introduce more diversity within the rebel fleet, which resulted in the creation of the MC80 Liberty Type Heavy Star Cruiser. The ILM crew nicknamed the Mon Calamari ships "pickle ships" due to their rounded pods. The unique shapes meant the model makers could not use kitbashing techniques, and the parts for the models were created at ILM. Concept designers Joe Johnston and Nilo Rodis-Jamero envisioned the Mon Calamari ships as streamlined vessels.
Within the Star Wars Legends continuity, the reference book The Essential Guide to Warfare, authored by Jason Fry and "Paul R. Urquhart," established the starship as the MC80a Star Cruiser. In the current Star Wars canon, the MC80a Star Cruiser designation is assigned to the MC80A Home One Type Heavy Star Cruiser, a distinct MC80 Star Cruiser variant that is referred to as the MC80 Home One type Star Cruiser in Legends.