The first one really reminds me of giant tortoises, like the ones from Galapagos. The second one is also giving me tortoise vibes, though I see a bit of sauropod dinosaur in it as well. The third is almost certainly a camel, and the fourth is either a large flightless bird or maybe another dinosaur, this time a bipedal runner.
Whatever they were inspired by, they look absolutely amazing! Such creative designs, would love living in any of these. Great job!