That is correct. "I told you about the walrus and me, man. Don't you know we're as close as can be, man. Well here's another clue for you all. The walrus was Paul"
Actually there was theory that Paul had died in a car crash. A DJ in Detroit (I think) looked at a picture of Paul in the early days and a picture of Paul in the later days and came to the conclusion that it was not the same person. Some how that spread around the country and eventually it got back to the Beatles. The Beatles thought it was funny and started dropping little hints here and there in their songs and on their album covers that Paul was dead.
On the back of Magical Mystery Tour the Beatles are dressed in animal costumes. Paul is wearing a walrus costume. Allegedly the walrus is a Norwegian death symbol. Glass Onion was probably the most overt Paul is the walrus clue. Matthew Broderick got it wrong in Ferris Bueller's Day Off when he said John was the walrus.
The song She's Leaving Home makes reference to the day and time that Paul was supposed to have died. On the White Album the collection of noises called Revolution 9 when played backwards has a car crash with Paul yelling "get me out. get me out". And then every time John says "Number 9" forwards, played backwards he is saying "Turn me in dead man".
On Sargent Pepper's Lonely Hearts Club Band they introduce a fictional character to the band named Billy Shears. Allegedly there was a Billy Shears who won a Paul McCartney look alike contest. He was supposed to have replace Paul in the band.
On the Abbey Road cover John is dressed like a preacher. George is dressed like a grave digger and Ringo is dressed like an undertaker. Paul is barefoot and his eyes are closed and is dressed for burial. Paul is also the only one out of step with the rest of the band. On the back of Abbey Road there is a picture of a wall with tile insets that says Beatles. Just to the left of that tile inset are a series of dots that when connected make the number 3 as if the say "3 Beatles". Also on the front cover, even though it is wrong, there is a Volkswagen with a license plate that says "28 IF". Paul was already older than 28 but the idea is that Paul would have been 28 if...
At the very end of Strawberry Fields Forever, as the song is fading out you can hear George say "I buried Paul".
There are a few more but you get the idea. The Beatles were just having fun with this idea that Paul had died and had been replaced.
