How did the idea of naming all plugins after animals came to be?
It’s because of the rhinoceros being an animal.
The first plugins by RMA got animal names as well Flamingo, Penguin, Bongo. Later third party developers started creating plugins many of which were named after animals.
Rhinoceros used to be a temporary nickname while developing the software. Due to trademark issues it was adopted as the official name.
=) That was it, Durer was inspired by Rhino.
He used early beta of Penguin.