The subtitle of "I Am the Walrus" was No, you're not, said Little Nicola. She was right. In "Glass Onion", on the subsequent "White Album": "the walrus was Paul", and he was wearing the "walrus costume" on the Magical Mystery Tour cover. The walrus is associated with death in certain cultures, or so I've read, in the various explanations of the
clues to Paul's death to be found in Beatles lyrics.