Prone to aggressively and repeatedly biting, injecting a vicious neurotoxic venom with each nip, this spider is a bastard. But the part that’ll make you cross your legs is the side effect of its venom: If it doesn’t kill you, it’ll give you the most painful erection of your life, one that can last days and potentially leave you impotent. Basically, it’s a spider that ruins boners. Which might well be the single worst thing ever.