Right now? One... but there are many penguins that could be added at a later date; at least 17 species, compared to the sloth's 6... not that a lack of options for recycling a rig seems to matter; there's already several animals that have no obvious clone options...
Thank you for that answer to the question, yes, that's kind of of what I meant. Even though we have King Penguins, there are still requests for other species of penguins (same for otters). In most requests for sloths, it's "mostly" just the want of a sloth in general. I really doubt most people expect there would be two different species of sloth and 9 out of 10 of them would be happy with whichever one they chose, if they chose one at all. Also, sloths, while popular requests, were nowhere near as popular as otters and penguins. Or meerkats, if they come.
But hey, before anyone thinks I'm against sloths, by no means, They're very high up on my want list.