I mentioned these interesting animals quite recently, now here's one "singing"!
The hyrax species are actually rather vocal, and are capable of making a variety of noises. I even found a video of one taking on a much larger male baboon and making some interesting aggressive noises. They are also known for making an unusual sort of noise while chewing their food. They also have a bird-like cry that I do not know the purpose of. I can't help but find these odd little animals fascinating. As I mentioned before, their closest living relatives are elephants and the dugongs and manatees. Most of the species are found in Africa.