I have a habit of making up my own lyrics to famous songs two of the one’s that make me laugh are…
Any Dream Will Do…“I closed my eyes, drew back my foreskin”
Bohemian Rhapsody…“Mama just killed a man, put my bum against his head, farted now he’s dead”
Anyone else do this? 
My best friend does! Britney’s Born to make you happy’ is ‘Born to make you coffee’, a line in Toxic has been changed from ‘Do you know that you’re toxic?’ To ‘Do you know Sandi Toksvig?’
There are more, but those are the first two that spring to mind!
My younger sister used to do this but she’d end up making the songs about our family dog.
She took the lyrics from one of my favourite songs ‘Walla Walla’ and changed the lyrics from “Honey, Honey. Don’t you cry” to “Doggy, Doggy. Doggy of wonder
”
And another one of my personal favourites Linkin Parks ‘In the end’ went from “I tried so hard and got so far” to “I barked so loud and got no where” 
I used to sing to one of my previous dog’s quoting from The Beatles’ She Loves You “I’m so glad that she’s my little girl” they’re the actual lyrics but she was a fabulous companion. 
Beyond my festive rendition of Dildos and Wine shared numerous times already on this forum, I can’t immediately think of any.
However… a little while after reading your post, I was perusing Facebook and a story about Julie Andrews turning 79 came up which fits your topic beautifully and I feel the need to share… she performed, “My Favourite Things” with these new genius lyrics:
Botox and nose drops and needles for knitting,
Walkers and handrails and new dental fittings,
Bundles of magazines tied up in string,
These are a few of my favorite things.
Cadillacs and cataracts, hearing aids and glasses,
Polident and Fixodent and false teeth in glasses,
Pacemakers, golf carts and porches with swings,
These are a few of my favorite things.
When the pipes leak, When the bones creak,
When the knees go bad,
I simply remember my favorite things,
And then I don’t feel so bad.
Hot tea and crumpets and corn pads for bunions,
No spicy hot food or food cooked with onions,
Bathrobes and heating pads and hot meals they bring,
These are a few of my favorite things.
Back pain, confused brains and no need for sinnin’,
Thin bones and fractures and hair that is thinnin’,
And we won’t mention our short shrunken frames,
When we remember our favorite things.
When the joints ache, When the hips break,
When the eyes grow dim,
Then I remember the great life I’ve had,
And then I don’t feel so bad
ETA I googled it to see if I could find a video and turns out it’s fake news and old fake news at that, but I wish it was a true story. Whoever wrote the lyrics is still genius and it would be wonderful if Julie Andrews had sung them… I bet she would have if not for the botched vocal surgery!
Well it could encompass misheard lyrics as well as made up one’s! That is so funny!
Hot Chocolate-You Sexy Thing.
“I believe in milko”
I had no idea what milko was, but i believed in it! 
Guilty ! The funny thing is that remembering all the twisted lyrics I use and especially what song they go with is hard . Once I start I usually do multiples in a row . Often my modifications are satirical of nature . Thanks @WillC , now I will be thinking of my twisted versions and try and write some down .
I’m the same, the two examples i posted are the one’s at the forefront of my memory, but if i hear certain songs on the radio or on my phone shuffle the made up lyrics come flooding back even though i have forgotten the songs!
Hermans Hermits.
No Milk Today.
No Milk Today. My love has gone away.
She went off in the Van. With the Young Milkman!!!
I always heard and sang Milko too!
@Peitho … 
youve given me an earworm…cant get that bloody tune out of my head…i started whistling it involuntarily !!!
" How can you have any pudding if you don’t beat your meat " . I was thinking of many of my lyrics and determined many of them may be a bit vulgar to many , and the recent phenomena of being "politically incorrect " . I do find it strange I can not think of too many while trying to remember them .
Has to be said in a broad Scottish accent!
Yes it’s a strange phenomenon, i have literally thousands of songs in my head that if i hear a one or two second intro i can immediately name and can sing along to the lyrics no problem. But ask me to remember or recite those lyrics in isolation, i can’t!
Haha!! Yes!!! I do this often too!
Wet Wet Wet
I feel it in my fingers, i feel it in my toes.
Love is all around me and so my penis grows. 
Atomic kitten … lick my hole again
Call that one the arthritis song.
Splinter song. I got you under my skin !!
Deep in the heart of me.
Take That want you back. Renamed oh my back. Oh my legs. Overdone at the gym. Feeling old!@@
Ashford and Simpson-Solid as a Rock=Constipation
Kings of Leon-Sex on Fire=Thrush
Please delete link if inappropriate. Rick Astley did a version of his famous hit with Specsavers audiology to highlight how people mishear things when going deaf.
It’s pretty hilarious
