My lifelong #1 fear/most hated thing on earth: Birds.
Reasoning: Birds are disgusting, nasty, unpredictable, evil little beasts. They can and will attack, peck, gouge, and maim unsuspecting and undeserving victims (of any species, including their own).
Summary of the Horrifying Story linked to above: Basically, the seagulls are decimating the whale population in Argentina because the nasty-ass birds are DIVEBOMBING and EATING CHUNKS out of whales when they come up to breathe/flap their tails/do cute whale things. The birds have discovered that whales make for nice sushi, so they just lurk above the water and grab a nice meaty mouthful (leaving an open wound behind, natch) whenever the whales come up. Not shockingly, the gull population has exploded and the whale population has plummeted (OH YEAH, THEY KILL THE BABY WHALES TOO). So now the Argentinians are having to figure out a way to "control" the gull population-- and by "control," we mean "kill," which should obviously be encouraged.
So sorry, but this article made me shiver for like two hours, because a) EWWWW; b) that is SO sad, poor cute baby whales; c) I ALWAYS KNEW BIRDS WERE EVIL; and d) IT IS ONLY A MATTER OF TIME BEFORE THE BIRDS TURN THIS SAME BEHAVIOR ONTO HUMANS. Think about your last trip to the beach: weren't those gulls a little close for comfort? And in light of this new information, on your next trip...yeah, have fun with that.
This is where I pat myself on the back for being ahead of my times with the bird-fear and trust that a lifetime of bird-wariness and bird-avoidance skills will come in handy during the eminent bird-apocalypse. To the brave people of Argentina on the front lines: I salute you.