Okay, that's enough of that. Obviously Mantis Eye: The Original Mantis Supply Store was this year's April Fools' gag. Hopefully it was one of the less lame ones you witnessed today, on a day when the internet is traditionally completely untrustworthy. I assure you there are no legal battles going on for the name of this site.
In case you didn't know (and I doubt you do), the joke site was also based on Mantis Place, which is a real (though non-crazy) seller of real, live mantises. They also probably have more trustworthy information, mostly because I didn't make that site up. You can still check out the gag site if you like, though the Mantis Buyer achievement is no longer gettable. Thanks for visiting!