Both of you, because you copied him All the species have now been named correctly at least once so far in this thread.
I was busy googling pictures of souslik ears whilst he was replying. When I bad come to a conclusion he had already written his answer, mine was original research though.
It is pretty much been established what 2,3,5 and 6 are and I'll agree with Brum that 4 is an Ocelot and agree with Crowthorne that 1 is a Prezwalski's Horse and I'll stick with North American River Otter so I'll go with; 1) Prezwalski's Horse 2) Pygmy Hippo 3) European Souslik 4) Ocelot 5) Onager 6) Okapi 7) North American River Otter That gets you HHSOOOO which is the chemical formula of Battery Acid
Przewalski horse Pygmy hippo European ground squirrel Ocelot Onager Okapi Giant Otter No idea what the hidden meaning is though!
Magpie Goose has discovered the answer, although I would prefer to write the formula as H2SO4 - it is, of course, sulphuric acid. Well done Anseranas semipalmata!
Here are larger versions of the photos, with apologies to the creatures who had their noses cropped to fit them in. The species are Przewalski Horse, pygmy Hippo, Japanese Serow, European Souslik, Ocelot, Okapi, Onager and giant Otter. The serow was very difficult, so the souslik was a better choice because it can also be called a European ground Squirrel, which still works. It would be churlish to argue about the otter species, because as far as I know all otters have very similar ears (with the possible exception of sea otters). I hope everyone enjoyed taking part. I am working on another quiz for next month, which I think will feature tongues. You have been warned