Huh. I learned:
Great big gobs of greasy grimy gopher guts
Mutilated monkey meat,
Chopped up baby parakeet
…
However, my Monkeys Jumping on the Bed was the sanitized version, and Little Bunny Foo Foo bopped his mice on the head.
Female, 25, Maryland
Bopping. Female, 30, NY
“Boppin’ 'em on the head.”
Male.
Another vote for boppin’em.
Female, 21, learned the song in Michigan. Always hated that song. I think it was the impending doom of the countdown (I’ll give you three chances…I’ll give you two chances…this is your last chance…). I got very nervous on Bunny Foo Foo’s behalf…
“No, little bunny! Don’t look in the window or the zombies will eat you!!!”
Plus, we never really knew what a goon was, which made the trasformation at the end all the more horrific.
wrong wrong wrong… 
Bopping, Male, Seattle 1967-1985. But to be fair I never heard the rhyme until I was in the Army in 1993. Heard it from a guy from New Orleans. Those were complex times.
Female, 30s, northeast U.S.
It was “boppin”, and the bumping / “no more monkeys” version of Five Little Monkeys song, and we did the “mama” version of popping off the dandelion heads.
But our version of the GreasyGrimyGopherGuts didn’t have a unique fourth line, and the last line was slightly different:
Great green gobs of greasy grimy gopher guts
Mutilated monkey meat
Dirty turdy birdie feet
Great green gobs of greasy grimy gopher guts
And I forgot my spoon!
I’m a boppin’ 42-year-old male from Alabama.
Same time. Same place. Same bopping. Learned it in school, so there was no gender distinction.
Evil Sauron foo-foo blazing in the tower
Seeking out the ring bearer and fukkin with his head!
Yep, the secret sauce was chopped baby parakeet for me too.
Male. 39. North Carolina.
Little Bunny Foo-foo would usually bop the field mice, but would occasionally bonk them, too.
The monkeys would break their heads, but when Mama would call the Doctor, the doctor would say, “No more monkeys jumping on the bed.”
And a lovely meal would consist of:
Great green gobs of greasy, grimy gopher guts
Mutilated monkey meat
Little, dirty birdie feet
French fried eyeballs rolling 'round the toilet seat.
Oops, I forgot my spoon,
But I’ve got my straaaaaawwwwww.
I never heard of Little Bunny Foo Foo as a kid; I learned it from my wife. She sings, “And bashin’ 'em on the head.” I like that better than “bop”.
Male, 39, MD, Boppin’
My memory:
Great big globs of greasy grimy gopher guts
mutilated monkey meat
chopped up baby parakeet
French fried eyeballs floating in a sea of blood
and I forgot my spoon
…but I brought my straaaaaaaaw!
Never heard the monkeys on the bed.
Great green globs, etc.
Mutilated monkey meat
Putrefacted piggie feet
French fried eyeballs - goodness, what a tasty treat!
And I forgot my spoon. (No straw available.)
Pretty sure the piggie feet line is my own invention, as I didn’t like whatever it was I replaced.