Arena Homme Plus, a men's fashion magazine from Japan, featured characters from the game modeling Prada's summer collection in 2012.
Even though Ultros claims to be an octopus in his DLC Coliseum fight, he only has 7 tentacles. This makes him neither an octopus (eight tentacles) or a squid (ten tentacles).
During a cutscene where 'The Chaos' attempts to grab Lightning, there is a hidden message among the yellow lines as she disappears. The message says "Pray for Japan" which was not known because it was written in a different script (Etro Script, a 3rd type of language used in Final Fantasy XIII). This is most likely a reference to the 2011 Tohoku Earthquake in Japan.