Anna Rex is a clothing company in Grand Theft Auto IV. Advertisements for the company is seen all over Liberty City. It is featured in the in-game website www.peepthatshit.com in the "Street Fashion" section. The name of the brand is derived from anorexia - an eating disorder. The name can also be a parody of stores such as Anne Taylor or Lane Bryant - both are names, however, Lane Bryant is a plus-size store.
It also returns in the upcoming Grand Theft Auto V, as seen in the released artwork.