Multinational Species Conservation Funds Semipostal Stamp Reauthorization Act of 2012 - Amends the Multinational Species Conservation Funds Semipostal Stamp Act of 2010 to require such stamp to be: (1) made available to the public for an additional four years; and (2) offered in a a choice of five versions depicting an African or Asian elephant, a rhinoceros, a tiger, a marine turtle, and a great ape.