I randomly remembered an old horror story anthology I read when I was younger, the book was at the local Toronto Public Library. I can remember a couple of stories from it.
One was about a boy whose uncle invented a machine that allowed a human to levitate. I remember the machine being unpleasant/painful to experience, but the longer a human can endure the higher they can float. They encounter a "cloud monster" that look sort of like a floating squid, which the uncle scares away with a sort of weaponized laser-pointer. Later, the boy hears the machine had exploded and killed they uncle, and he wonders if the creature somehow was responsible.
There was another one about a girl who gets a box in the mail to watch for a neighbour. The neighbour is suspected by the local children of being a witch, despite warnings to the contrary, the girl opens the box and sees a small, dry shriveled thing she flings away in horror. The creature grows in the dark and eventually the witch shuts her in a room with it saying she "shouldn't have opened the box", the creature reaches for her while saying "hello INSERT NAME HERE". The monster in question was sort of purple, with yellow fangs and an almost boar like head and tubes/spines on it's back.
The third story involved a bob-cat being brought along on a space voyage, and finding a sort of alien tiger, only longer and with one horn that when angry started inhaling air and growing, the entire story was from the bob-cats perspective. They all were illustrated with a very old school style
I think there was another story about a boy who goes on a spaceship to escape a family vampire curse, he winds up on an alien planet whose inhabitants, looking slightly like kangaroos, have a blood letting/drinking ritual involving their long eared cattle-esque heard beasts, but that might be from unrelated collection.