Horton Nutria was an Earthling, the brother of Arthur Nutria and the uncle of Walter Nutria. By a rather odd coincidence he looked exactly like every member of the Lirgonian species, which his nephew encountered. That is to say, chubby, middle-aged, with a big lumpy nose and always in need of a shave. Fortunately he refrained from wearing red pajamas all the time.
Horton owned a pool hall in East Weston called Nutria’s Billiards which was commonly frequented by a range of somewhat disreputable characters and activities of dubious legality, in which he occasionally participated. Although Walter was forbidden from visiting the pool hall, Horton kept his lips sealed about the visits that his nephew and Yselle Meridian made when they could. On one occasion he even leant the boy a pool cue, which then lay hidden in his closet for a month until he could return it.
In spite of, or perhaps because of, his sometimes disreputable behavior, Horton became a source of advice that Walter turned to in times of need. For example, when called upon to lead the Lirgonian ship Gilded Excelsior into battle and unsure of what to do, he remembered Horton's maxim "If you can't do something right, at least do it attractively." Later, when trying to score with Yselle, he kept in mind "When in doubt, keep your big yap shut."
Horton was unfazed when Yselle came to visit him in the company of the barely-disguised Snartmer and Burkhardt. He was quite used to seeing some very strange people. After Walter finally returned his pool cue, he arranged for Jimmy Fortinbras, who spent a lot of time at Nutria's Billiards and owed him a favor, to drive his nephew in a limousine to the Tulip Extravaganza dance.