The list of Blik wall decal patterns I haven't mentioned is growing. Eames? Helena Christensen? There's a Space Invaders [Space? Can I say Space? Or might it be better to just call them Invaders? On the apparent advice of Blik's counsel, I'm going with the latter.] set, which comes in a bunch of colors and in black or white, too.
If easily installed and removed wall stickers aren't permanent or expensive enough for you, there's always the original Invader, that anonymous French artist who's been installing mosaic tile Invaders guerilla-style all over the world for a decade or so. His Invasion Kits used to be EUR900 in his gallery, then they were EUR30 at one point [gee, glad I waited], now they're available online for EUR90 [d'oh!] an invader. If you're doing an entire bathroom, I'd start saving now.
And in other Blik 8-bit news, the Blik robot decals I thought I saw Yoyamart but couldn't find online weren't a hallucination: turns out they were a custom design for Giant Robot. They're now available as a product, with color-coordinated menacing eyes.
Blik Invader starter set with seven invaders and a base is $45, and 3-alien add-on sets are $12.50 [whatisblik.com]
Wow, Target has Blik? And they're not knockoffs? Invaders in black are just $36 [target via dt reader kerry]
Okay, now I am confused -- on the Target site (as well as implied in your post), it says the decals are easily removed. However, the "tips" section on the Blik site does not mention this fact. In fact, the site says they are very sticky. Are these two different types of wall decals?
Blik actually does have two different types of wall decals - their original decals which are not repositionable, and the new Wall Sticks products which are repositionable. I believe that Target carries some of the Wall Sticks.