Put a herbivore with a penguin. After a fight, all penguins will be evil.
Get a happiness rating of over 90 for the penguins and they will do a happy dance.
Put an insect house in a crocodile's exhibit. A swarm of killer bees will attack your guests.
Get a happiness of over 90 for the lowland gorillas and they will do a happy dance.
Put all the animals in the same exhibit then set them free. They will tear down your trees, trample your paths, and reduce your buildings to rubble.
Put a male and female of your favorite animal together and they will give birth to a free animal.
Place a lion, tiger, and a bear in an exhibit.
On game date December 25th, you will be able to buy Christmas Trees and Frosty the Snowman for your zoo.
Build a water tank around a group of guests. The tank will fill up with water and the guests will start to swim.
When your guests are looking at an animal from the side of an exhibit, quickly pause game play and build another exhibit around the guests. Place some lions or crocodiles in the exhibit and resume the game. The guests will begin running around screaming.
Set your system date to October 31 or November 1 and all guests and buildings will turn orange and black. You can also see buy a jack-o-lantern at the buildings and items menu and see a witch fly overhead.