Where did the name Rhinoceros come from, and why is everything named after animals?

The legend goes that Michael Gibson, who worked on Sculptura, was a fan of Rhinoceri and had pictures of them hung up in his workspace - hence how the project got its nickname - which was, again according to the legend, somewhat of an in-house humorous reference.

After that the trend of naming the other products in the McNeel software line after animals continued, and that has spread to many people who have created plug-ins and accessories for Rhino plus Grasshopper.