A boreglunch is a type of alien-originated animal that is often found as vermin on starships that travel from planet to planet without proper precautions taken to secure cargo, akin to an Earth rat. Boreglunches can be recognized by black and red patterning and a set of delicate antennae.

Making tricorder scans of the engineering hull of the time travelling starship Nautilus, Spock noted both rats and boreglunches taking residence on that vessel. (TOS novel: Crossroad)