The tabby will become a "Doctor of Litter-ature" in recognition of his contributions to the Castleton campus, where he has become a regular visitor for the past four years.
For you MST3K fans, this proves that cats are superior to Nick. Even cats get into Castleton.
TL;DR: Why are they giving an honorary doctorate to a cat?
A: Because they like him! They really, really like him!