I'm pretty sure Stanford was founded by two individuals and they never discussed the mascot. One went to fill out the paperwork and put the mascot as the Cardinals, unoriginally thinking it up on the spot. In the meantime, the other one was handling the press around the new university and was being interviewed by a newspaper reporter. The reporter asked about the mascot and the founder panicked, realizing that it had never been discussed or agreed upon. He looked around and saw a sickly tree a few feet away. He pointed it out to the newspaper reporter and the rest is history.