A pus hog was an animal from the Delta Quadrant, similar to an Earth pig.
In a delusion experienced by The Doctor in 2371, in which the crew installed additional holoemitters aboard the USS Voyager, Neelix called an invading Kazon a pus hog as he fended him off with vegetables and kitchen utensils. (VOY: "Projections")
Neelix, initially jealous when Tom Paris gave Kes a locket for her second birthday, later assured her that she had "seen the last of that green-eyed pus hog". (VOY: "Twisted")
After Dal R'El and his crew deceived the Diviner into taking the USS Protostar without its proto-drive, Jankom Pog said, "Jankom Pog takes to acting like a pus hog takes to phlegm." (PRO: "A Moral Star, Part 1")