One Flea Fly (They Were Only Playing Leapfrog)
(source: the song that I know, posted here, appears to be a mish-mosh of two songs - "Flea Fly" and "The Grasshopper Song" from "The World's Best Funny Songs", Esther J. Nelson, 1988.)
(same tune as "The Battle Hymn of the Republic")

As one flea fly flew up the flu
The other flea fly flew down (x4)

There appear to be two commonly-known choruses to this song. Pick whichever you like:

Glory, glory how peculiar!
Glory, glory how peculiar!
Glory, glory how peculiar!
As (repeat the verse)!

or:

They were only playing leapfrog!
They were only playing leapfrog!
They were only playing leapfrog!
As (repeat the verse)!

Other verses:

As one pink porpoise popped up the pole
The other pink porpoise popped down (x4)

As one slick seal slid up the slide
The other slick seal slid down (x4)

As one striped snipe snuck up the pole
Another striped snipe snuck down (x4)

As one giggly girl giggled a giggle
Another giggly girl giggled too (x4)

As one black bug bled blue-black blood
The other black bug bled blue (x4)

As one pink poodle paddled up the pool
The other pink poodle paddled down (x4)

As one hedge hog edged up the hedge
The other hedge hog edged down (x4)

A busy buzzing bumble bee,
Was busily buzzing by (x4)

One photographer photographed
Another photographer's back (x4)

A spider espied a spider,
On another spider's back (x4)

One dumb digger dug into the ditch,
While the other dumb digger dug out (x4)

One black bear backed up the bank
While the other black bear backed down (x4)

As one red rooster raced up the road
Another red rooster raced down (x4)

A big black bear bit a big black bug
And the big black bug bled blue (x4)

As one cruel croc crawled up the creek
The other cruel croc crawled down (x4)

As one strong swimmer swam in the sea
The other strong swimmer swam out (x4)