How do you unlock the tiger hamster in hamsterz life 2

You have to keep talking to the shop keepers, eventually the first one, (the boss), will say hes going out, when you visit the shop there will be more stuff, and hopefully new breeds. There are two unlockable breeds. The tiger hamster (which everyone is talking about) and the Raccoon hamster (i wanted a new hamster and randomly found it in the shop)