I don't go crazy and try to make really weird creatures. I believe in convergent evolution. That theory states that given similar conditions in two independent environments, evolution will select similar solutions.
Well, it works to a point. It helps if you start with a similar body plan. We have "mole like" and "squirrel like" animals that have evolved within several different groups of mammal, for instance. And thylacines (an extinct marsupial) bore a superficial resemblance to some carnivorous placental mammals. But we don't see "mole like" birds, because birds are two different from mammals to be molded into something like a mole. And we definitely don't see "mole like" earthworms and "mole like" echinoderms, because those animal phyla started with completely different body plans than vertebrate animals, let alone mammals, did. Burrowing forms have evolved in those groups, but they've developed different adaptations to that life style, ones that take advantage of the body parts they started with.
It's unlikely that you'll see a lot of convergence between, say, an arthropod (an animal phylum based on repeated pairs of legs and an exoskeleton and a ventral nerve cord) and a vertebrate, which is based on a skull, an internal support structure and a dorsal nerve cord, aside from very superficial things. You might see superficial convergence. For instance, snakes lost their legs and became more wormlike in shape, but they're still vertebrate animals with a backbone and lungs and all that,
not worms. Even the different kinds of animals we call worms today come from different phyla and are very different in structure when we examine them. An earthworm is far more different from a tapeworm than we humans are from snakes.
So I seriously doubt we'll see anything that is exactly like a vertebrate animal, let alone one that's nearly indistinguishable from a specific species, like a rabbit, on an alien planet. It's actually easy to imagine an alternative reality where vertebrate animals didn't evolve at all on Earth.
Pikaia, the earliest chordate fossil we've found so far, does not appear to be an especially abundant or widespread species compared to the earliest members of other animal groups (some of which are now extinct). If its lineage had gone extinct, none of the animals with backbones would have evolved at all on this planet.
Of course, with SF, we can speculate with all kinds of what ifs that could allow similar forms to evolve on distant planets. Even though I doubt it's probability, I enjoy reading stories with aliens that look like they evolved on Earth. To be fair to SF writers, it's darned hard for even a biologist to fathom a body plan that's not remotely based on any of the ones that have evolved here, let alone make it relatable to the sentient vertebrates who are reading the book.
