It's a morph of Princisia vanwaerebecki. If you keep a good size breeding colony of the tigers, you will eventually produce some of the other Princisia morphs in that colony. The other morphs aren't really apparent though until they become subadults-adults. Also, Gromphadorhina grandidieri is a different species altogether that no one in the U.S. seems to have yet. They look kind of like the black morph G. portentosa and don't have any of the Princisia red/orange markings down their sides.
Herp13, Xelda answered your question "tiger hissers" are a morph of Princisia vanwaerebecki, I agree they are a morph of Prinicisia vanwerebecki, unless you can prove they are Gromphadordina grandidieri, then really its just irrelevent.