Bissops were a type of non-sentient creature, specifically a lizard-hound hybrid, that the Yuuzhan Vong species, who are sentient, utilized. These creatures were bred by the Yuuzhan Vong for the purpose of locating and pursuing living beings; bissops were carnivorous animals that relied on their snouts to find their prey. During the time of the Yuuzhan Vong War, Yuuzhan Vong warriors employed bissops to hunt down prisoners attempting to escape, as well as enemies who had managed to infiltrate Yuuzhan Vong territory on various worlds, including Selvaris and Caluula. Furthermore, in 29 ABY, bissops were used to pull the sled belonging to Supreme Overlord Shimrra Jamaane during a ceremony that took place on the planet Yuuzhan'tar.
Bissops, which resembled a cross between a lizard and a hound, were selectively bred by the sentient Yuuzhan Vong species because of their innate tracking and hunting skills. These creatures were low to the ground and had elongated snouts that gave them an excellent sense of smell. Bissops possessed skeletons and claws on their feet, the latter of which left distinctive marks in the dirt. These creatures were physically strong enough to carry a fully grown Yuuzhan Vong on their backs using a saddle, and they were also agile and quick. As a life form connected to the Yuuzhan Vong, bissops were vulnerable to the effects of the dangerous Alpha Red pathogen.
Bissops were classified as non-sentient and would sniff at both the ground and the air when tracking something. They would also emit braying and howling sounds when actively pursuing a moving target. As carnivorous creatures, bissops were generally docile enough for some Yuuzhan Vong to ride them with saddles, or for others to use them to pull sleds. However, if attacked by an enemy, bissops would quickly attempt to strike at their attackers. These hounds were typically accompanied by Yuuzhan Vong handlers while hunting, and they usually hunted in packs. Bissops were trained by their masters to return to a designated base camp if something were to happen to the rest of the hunting team.
Bissops were initially bred around 27 ABY and were subsequently used by the Yuuzhan Vong during the Yuuzhan Vong War when they launched an invasion into a galaxy that was not their own. Typically accompanied by Yuuzhan Vong warriors during hunts, bissops served as hunters and trackers for the Yuuzhan Vong, playing a role in their war efforts. In 29 ABY, on the Yuuzhan Vong-controlled world of Selvaris, bissops were deployed in an attempt to capture prisoners of war who had managed to escape.
The hounds were also present on the planet Yuuzhan'tar, which the Yuuzhan Vong had captured from the New Republic. On Yuuzhan'tar, bissops were occasionally used to transport high-ranking Yuuzhan Vong in saddles. It was also on this world that a pack of bissops pulled the sled of Supreme Overlord Shimrra Jamaane during a ceremony held at the Place of Sacrifice. Bissops were also found on the Yuuzhan Vong–controlled planet of Caluula, where three of these creatures accompanied a squad of warriors as they tracked a group from the New Republic across the planet's surface in 29 ABY. However, because the entire Yuuzhan Vong hunting squad had been exposed to the Alpha Red pathogen and weakened by it, the New Republic group was able to easily kill both the warriors and the bissops.
The first mention of bissops occurred in Elaine Cunningham's novel, The New Jedi Order: Dark Journey, which was released in 2002 as part of The New Jedi Order series. The hounds then made their initial appearance in The New Jedi Order: The Unifying Force, a book written by James Luceno and released in 2003, serving as the final installment in The New Jedi Order series.