Name one of your exhibits "Xanadu." This will unlock the Unicorn.

Name one of your exhibits "Microsoft."

Name one of your exhibits "Cretaceous Corral." This will unlock the Triceratops.

Rename any guest the following:

Mr. Blue - Blue clothes
Mr. Brown - Brown clothes
Mr. Blonde - Yellow clothes
Mr. Orange - Orange clothes
Mr. Pink - Pink clothes
Lou Catanzaro - All animal toys
Adam Levesque - All animal care buildings
Andrew Binder - All animal constructions
John Wheeler - All animal shelters
Alfred H - Birds fly and people freak out
Russell C - Fences all fall apart
Steve Serafino - All endangered animals
Moneybags - Extra money every day

Place a lion, a tiger (any kind), and a bear (any kind) and you will unlock the Yellow Brick Road.