Doclector said:
Good sir, I, too, suffer the same problem.
I bought Minecraft because I played it at my friend's house and it was fun. We spent the first night running away from zombies and creepers. So I got my own for the same reasons you described. And then I ran into those stupid spiders. pitch black, HUGE spiders with red eyes. Can't even stand to look at them from afar. I could probably take them out with my wolves and bow and arrow, but I'm just scared of them! Same with Creepers popping out of nowhere, exploding in your face. Or just random enemies coming from a dark corner at you while you're mining innocently somewhere. But yeah, mostly spiders.
So know what I did? I set it on Peaceful. I've been lucky enough to find string on dungeons and to have some leftovers from when I was playing on Normal. So I figured I was fine. Oh, how silly I was.
As it turns out, squids look a lot like spiders: large, black, multi-legged creatures. They don't attack you...but they do like to show up for no reason in caves with waterfalls. So imagine my surprise/horror when I was mining and I saw three of them bundled together, half swimming, while I was mining. I swear I thought they were spiders at first so I didn't even bother looking back. I ran away.
So yeah, those I can't get rid of. Oh, and slimes. Freakin' things look like HUGE Creepers. Scared the hell out of me.