Mammal Defense Shield
From Multiversal Omnipedia
The mammal defense shield was a planetary forcefield designed for the Toad Empire by Al Negator, and erected to protect the conquered Rigel 5 from mammal invasion. It repelled any warmblooded individuals. After the liberation of Rigel 5, Willy DuWitt recalibrated the defense shield to repel toads instead, so the toads could never return.
