The Enfield like their Fox cousins make excellent pets, they share the same habitats and diet. Their ability as hunters is exceptionally precise combining excellent telescopic vision as well enhanced hearing make them formidable indeed. They are distant relatives of the Owlursus and are barely a tenth of the size. Taming them is exceptionally easy but they are excellent hiders and are rarely seen.
While typing up the description I totally forgot to mention their use as a familiar...I'm sure they would be quite excellent. In D&D your character has no control over the type of familiar that answers the magical summons but in Galaxy Five you can control the type of familiar summoned simply by having it present at the time of casting. It changes the ritual from one of summoning to one of binding. But I digress this thing would make an awesome pet and of course a familiar.