A pengvwin is anyone who acts like they have something they don't. This can be a physical attribute, mental or simply a possesion. They usually are very annoying too.
Pengvwins can be found very often in the British chav culture, as the small midgets within large groups. Also female pengvwins can be found attached to groups of popular girls groups, acting like Barbie while they actually look like a very masculine Ken.
Hey, see that pengvwin? He's only a lil skinny kid and he's hanging out with those huge biker dudes acting tough.