Well, we might get some lulz out of this thread, eh? As the title says, this thread is all about recalling things your opponents did that only a n00b would. I'll start things off, ofcourse.
This was quite some time ago, but this idiot n00b said no legendaries for the battle, so I kick his arse with just my Salamence spamming Dragon Pulse (... he had choice specs), so he's down to his final poke, right? So what does he send out? Mewtwo! I couldn't care less if it was say, an Azelf or a Zapdos, but an uber? Bullshit! But guess what happens? Salamence outspeeds and OHKOs anyways. :P
Now then, it's your turn to share your enemies' facepalm moments.