Say I play Blaine's Quiz Show and put Giratina Prism Star down, but my opponent just says "Giratina". Do I get 4 cards?
Yes, you do. Your opponent needs to name the full name on the card.
Source: WotC Chat (2001-01-18), TPCi Rules Team (2019-08-01)

Relevant cards

Note: All applicable cards may not be listed below.
SM11_186
SM11_186