what are the meaning of the following words please?

[john3_10]

walrus gum-boat

spinal cracker

roller coaster

[albertino]

The content of the lyric below is odd to me as a non-native speaker. Could any knowledgeable teachers or Beatles' fans give me an explanation to the verse in detail? Thank you.

Come together by Lennon/McCartney

Here come old flattop, he come grooving up slowly
He got joo-joo eyeball, he one holy roller
He got hair down to his knee
Got to be a joker he just do what he please

He wear no shoeshine, he got toe-jam football
He got monkey finger, he shoot coca-cola
He say "I know you, you know me"
One thing I can tell you is you got to be free
Come together right now over me

He bag production, he got walrus gumboot
He got Ono sideboard, he one spinal cracker
He got feet down below his knee
Hold you in his armchair you can feel his disease
Come together right now over me

[Right!
Come, oh, come, come, come.]

He roller-coaster, he got early warning
He got muddy water, he one mojo filter
He say "One and one and one is three"
Got to be good-looking cos he's so hard to see
Come together right now over me

Oh
Come together
Yeah come together
Yeah come together
Yeah come together
Yeah come together
Yeah come together
Yeah come together
Yeah oh
Come together
Yeah come together

[Ouisch]

Much like "I Am the Walrus," "Come Together" is just a bunch of words that John Lennon strung together because he liked the sound of them. They don't have any context and no real meaning.