Since I haven’t done one of these in a while…
In the “scientific names that sound silly” department, I present the eagle owl, Bubo bubo. Somehow that doesn’t sound like a fittingly fearsome name for a bird that is its ecosystem’s top predator (it will eat other birds of prey, like buzzards and goshawks). Bubo is the actual Latin name for this species (and other large owls). I’m unclear as to the relation of this word to bubo, as in bubonic plague – both come from Latin, but according to the OED the plague-related one is originally derived from Greek. Fun fact: you can use the adjective “bubonic” to mean “like or relating to owls”; I think I shall do this more often.
Another, even sillier one: the fish Boops boops (that’s pronounced “BOH-ops”). Which leads me to an interesting difference between animal and plant scientific nomenclature. Animal names can be tautonymic; that is, they can repeat the same name as both generic and specific epithet. This is not allowed for plants—even if the words are in two different languages (for example, the brown bear Ursus arctos: ursus is Latin, arctos Greek for “bear”).
A more mellifluous species: Bocydium tintinnabuliferum (say it out loud!)—the specific epithet means “bell-bearer”, and here’s why. This is one of several related species of leafhopper bearing ridiculous thoracic ornaments for reasons no one quite understands.
In the misnomer department: the eastern mole Scalopus aquaticus, which is most certainly not aquatic. The story as I’ve heard it is that Linnaeus assumed the specimen he was sent was aquatic because it has nondirectional fur and paddle-like paws. However, the Wikipedia article on this species claims that the type specimen was also found floating in water. The whole business is a bit strange to me, because (1) Linnaeus certainly knew about moles; they’re found it Europe too and (2) Scalopus means “shovel-foot”, so he understood about the digging. So, a bit of a mystery to me.
More misnomers, or at least confusingly-named: if I asked you what sort of animal belonged to the genus Leopardus…you would be wrong is you answered “leopards”. Leopardus contains several small New World cats, including the margay and ocelot, which superficially resemble miniature versions of the true leopard, Panthera pardus. Here’s another one: Puffinus…a genus of shearwaters (not, you know, puffins). I find this one truly strange because “puffinus” is a New Latin word made from the English word “puffin”, which apparently did once describe shearwaters.
And, finally, in the “badass” category, the newly-described dinosaur Iguanacolossus fortis. Because what is more awesome than a giant plant-eating lizard?