Name a guest DINOMAN. The cheat turns off when you restart the game.

To Unlock Deinosuchus name a ready made exhibit 'Super Croc'.
To Unlock the Unicorn, Name a Ready-made Exhibit 'Xanadu'.
Unlock Triceratops by naming a ready-made exhibit 'Cretaceous Corral'.
Note: If you don't have a Ready-made Exhibit, then build a few exhibits, and then name the first one 'Super Croc' ect.

To get a mermaid in "Marine Mania" create a new tank, then if you have the mermaid statue you can put it in the tank, it will break open and become a mermaid.

To get more money, press SHIFT + 4 ($) to earn dough the easy way.

To unlock the Deinosuchus, complete all scenarios. Select "No" when the final scenario concludes and you will be told that the Deinosuchus has been unlocked.