A fishy tautonym
This is Boops boops in a bucket:
Boops boops—the bogue—is a stellar example of a tautonym, an organism that has identical genus and species names in binomial nomenclature. If you're in the market for a parasite-ridden, gut flora-infested, hermaphroditic fish, B. boops is your champion. It should be noted that the bucket pictured above is not representative of the bogue's natural habitat; most bogues are found down to 100 m in the eastern Atlantic.
As a general rule, tautonyms are less silly—though Chinchilla chinchilla and Banjos banjos are up there, and Amandava amandava seems vaguely reminiscent of a Harry Potter incantation. It is perhaps worth mentioning that tautonyms are limited to zoology (praise Linnaeus, such utter redundancy is not allowed in botanical taxonomy). Botanists, of course, circumvent this by altering a given plant's specific name by one letter. Because Ziziphus zizyphus is infinitely more reasonable than Ziziphus ziziphus.
Fun fact: As if Boops boops wasn't enough, the bogue also goes by Box boops.