The headcrab. Even its very name may make your lip curl in disgust. Yet one look at this little guy, transformed into a hat and sold by Valve, the studio behind Half Life 2 and the alien headcrab, will have you awww-ing in delight. And that's how it gets you.
The Headcrab Hat has an adjustable Velcro strap so, just like in the game, it'll fit any size head. After it's on you, not only will you enjoy an entirely unique look, but you'll also be the life of the party once the alien gets its four mind-controlling pincers into you, causing you to maul other guests and pour hors d'oeuvres into the giant maw you've grown that now bisects your torso. Charming.
You can get your very own head humper for $30, though the Combine Overwatch hints that living in certain areas of the country, such as Ravenholm, will get you one for free. What a steal!