Enter each code into the secret code box, which you access by clicking on the lock icon in the bulletin board (just to the left of the zoo entryway)

Effect	Password
A Homemade Dylo Doll is added to the bulletin board	DYLO
A Stuffed Toy Plane is added to the bulletin board	AIRPORT MANIA
Beta testing code that now give messages	MONEY
Beta testing code that now give messages	WATER
Developer thank-you message	RDC
Gives you 10 Park Benches	UTAH
Gives you 10 Trash Bins	EXCLUSIVE
Gives you 1000 Building Material	SHAKESPEARE
Gives you 1000 Money	SWEET THURSDAY
Gives you 1000 Research	GAMEZEBO
Gives you 1000 Zoo Points	ATHLETICS
Gives you 12 Black Street Lamps	NIGHTFLIGHT
Gives you 12 White Street Lamps	PALMYRA
Gives you 15 Conservation Points	SUNDOWN
Gives you 2 Drinking Fountains	MONTEREY BAY
Gives you 2 Hippo Drinking Fountains	HOGLE ZOO
Gives you 5 street signs	REFLEXIVE
Gives you 5 you are here signs	SWG
Gives you 6 Ferns	VAMPIRE SQUID
Gives you 6 Ficus trees	COTTONWOOD
Gives you 6 Globe Topiary Bushes	TCHAIKOVSKY
Gives you 6 Palm Trees	ULURU
Gives you 6 Pine Trees	GO COUGARS!
Gives you 6 Round Topiary Bushes	ATHENS
Gives you 6 Square Topiary Bushes	ADOL
Gives you 6 White Alamo Trees	JENNIFER
Gives you 7 Blue Flowerbeds	DUBLIN
Gives you 7 Red Flowerbeds	ASTORIA
Gives you 7 Tulip Flowerbeds	PRAIA
Gives you 7 Yellow Flowerbeds	KAYLEIGH
Gives you a Bear Statue	SHADOW
Gives you a Bridge	KOI
Gives you a Bridge	1673 4539 2601 4670
Gives you a Lion Statue	CLARK
Gives you a Turtle Statue	GALAPAGOS
Gives you a Water Fountain	BRIE
Gives you an Airport Mania Statue	INTERNATIONAL JETLINER
Gives you an Elephant Statue	CIRCUS PEANUTS
Makes the Mysterious Mansion available for purchase	ALORA
Makes the Saber-toothed Tiger available for purchase	REFLEXIVE GAMES ARE BEST
Makes the The Unicorn available for purchase	IWINBONUSITEM
Makes the The Woolly Mammoth available for purchase	STEAM POWERED
Makes the Yeti available for purchase	AMAZON
Martin Luther King Jr. quote	MLK
Question from developer about Simplz: Aquarium	AQUARIUM
Silly text message	123456
Text message, repeat it 5 times for different messages	M4N510N