Most people think John meant the "walrus" to refer to Paul
in the song "I am the walrus" from MMT.
BTW >>>It is also interesting to note that every complete stereo release of I am the Walrus reverts to a strange stereo mix - no treble on the left, and no bass on the right - beginning where John sings "Sitting in an English garden." The backstory: John recorded the radio clips "live" off-the-air, directly onto the monaural master recording. From that point, all stereo mixes essentially had to revert to mono midway through the song, in order to include the now-famous speech clips during the song's fade-out. <<<
