The Peekaru.



And yes, I checked, April Fool's Day isn't for another 7 hours. 

If there is a reason to like this garment, it is this image, and the other image that it immediately brings to mind.



It allows the viewer to more closely relate the act of childbirth to what it is:  an alien, implanted and growing inside its host, until it is ready to burst out, killing the host in the process (or at the very least, totally ruining her figure).