For starters, you can take an already good predator, for example, a cat, and make it invisible. In H. G. Wells' The Invisible Man, Griffin, tells Kemp, his momentary confident, the story of how he experimented on a cat before turning his invisibility machine on himself.
The bones and sinews and the fat were the last to go, and the tips of the coloured hairs. And, as I say, the back part of the eye, tough iridescent stuff it is, wouldn’t go at all...About two, the cat began miaowing about the room. I tried to hush it by talking to it, and then I decided to turn it out. I remember the shock I had when striking a light—there were just the round eyes shining green—and nothing round them. I would have given it milk, but I hadn’t any. It wouldn’t be quiet, it just sat down and miaowed at the door. I tried to catch it, with an idea of putting it out of the window, but it wouldn’t be caught, it vanished. Then it began miaowing in different parts of the room. At last I opened the window and made a bustle. I suppose it went out at last. I never saw any more of it.An almost invisible cat at large! Watch out rats, mice and the pigeons!
Not yet fully invisible. I need to make some fine tuning.
Griffin didn't mention if the things he made invisible retained their odors. If they did, an invisible cat's potential prey could still detect its presence by its odor.
Later in the story, when the violence-prone invisible man is on the run, Kemp reveals one of Griffin's secrets to the posse after him:
“Bear in mind,” said Kemp, “his food shows. After eating, his food shows until it is assimilated. So that he has to hide after eating.What about the feces? That is never explained in the book either.