Cerasus Ehllo was a male human serving as an Imperial officer within the Galactic Empire, and a member of the Ehllo family. The father of Cerasus maintained a personal relationship with the Galactic Emperor himself, Sheev Palpatine. Cerasus eventually achieved the rank of captain while serving the Empire.
Sometime between the events of 3 ABY and 4 ABY, he entered into marriage with Aryssha from the Starros Clan, who subsequently became pregnant with twins. Aryssha journeyed to the Starros family ancestral home situated on Hosnian Prime for the purpose of birth, informing Ehllo that she would reunite with him in approximately two time units. Growing impatient while awaiting Aryssha's return, Ehllo expressed his longing for her presence and arranged for a birthing suite to be prepared for her aboard his ship. Subsequently, he launched an attack on the clan's homestead, utilizing a squad of stormtroopers, in order to retrieve Aryssha and transport her back to his starship.
Following their arrival on the vessel, he escorted her to their designated suite before departing to attend to his responsibilities. Aryssha stealthily exited the suite and connected a datapad to the ship's computer systems. Upon being discovered by two stormtroopers, Ehllo reappeared and escorted her to partake in a meal. He presented her with Nosna fish, procured from Naboo, knowing it was a dish she enjoyed. Aryssha inquired about their destination, but Ehllo declined to disclose the information. She then requested a visit to Neral's moon to acquire some shoshak. Their conversation was interrupted by Gabe Bean, who informed Ehllo of a significant breakthrough in their research. He then exited the room after promising his wife he would consider the trip to Neral's moon.
Ehllo journeyed to the Corellian sector and escorted his wife to the bridge of his vessel. He offered an apology for compelling her to leave her family, admitting his fear of potentially losing her. They then returned to their quarters, but Aryssha departed to utilize the refresher. She trailed a pair of crewmembers, hoping they would lead her to Avon's journals. Ehllo and Phel Starros apprehended her and threatened to punish her.
The Imperial officer was positioned on his ship above Hynestia as Phel, aided by Marl Jibs, successfully captured Thea Starros and Mevera Starros. Following the infiltration of the King's Ransom by Lanitra and several allies, who incapacitated the majority of the crew with gas, Ehllo and a fire team of stormtroopers confronted them. He was ultimately captured by Deva Lompop when Sana transmitted Chadra-Fan opera at high volume into the helmets of the stormtroopers, effectively disabling them. She compelled him to guide her to the data cube containing Avon's journals. Subsequently, he was forced into an escape pod and ejected into the vacuum of space alongside Phel. Ehllo pledged to recover his family.