Eblis's species, the Kolkar, evolved on a world where due to a quirk of local biology (extremely fast decomposition of flesh once dead) it was absolutely essential for predators to eat their prey alive. Stomach acids keep the skin-dwelling bacteria responsible for the decay under control as a meal is digested.

Early ancestors used a sticky tongue to draw in meals but as the species grew larger they relied on powerful clawed forepaws to hold prey along with a elastic "trunk" armed with both powerful suction and internal muscles that work ridged rings of inward-pointing "teeth" inside the trunk over the meal. Once a Kolkar begins swallowing you it is extremely difficult to pull back out. It's easier to push in to release the grip, except that the suction will tend to keep you moving inward and you'd be lucky if you don't lose a few more inches into the sucking depths in the attempt.

Kolkar are perfectly able to digest bones, but they did not evolve the ability to digest hair or, for that matter, clothing, though the rare predatory kolkar often have themselves modified to be able to do this. (Eblis hasn't). The stomach is large and the digestive system simple, with indigestibles tending to make their way all the way through the body rather than being coughed up.

One result of this is frequent work for Eblis's plumber, who is always extracting hair, shoes, and assorted clothing from the depths of Eblis's toilet. Even the extra-large pipes you would expect from the home of a 700-pound alien are not wide enough to let this sort of thing through. The plumber has made every effort to not realize exactly what is going on and blames it on his non-too-bright employer.

Eblis's first sapient meal was, of course, a fellow kolkar, as were most of his subsequent ones before he came to Earth. Back home, memory backups and flash cloning made even being eaten merely an interesting diversion. He hasn't quite worked out that all the screaming and struggling he gets from his meals around here is for real.

Fortunately, though they have to let him do his horrible things to people due to political issues and his wealthy family, his long suffering "minders" (who he doesn't even know about) reform and memory-alter most of the people he eats. It doesn't make him any less horrible but at least he's sorta innocent about it and very few of his victims stay dead.