Years ago when I was in church camp, the song leader (a lady named Iris Bell) had us singing the "Oh, Nickodemo" song as a round. It was apparently a bunch of nonsense words strung together but we had a blast singing it.

Anyhoo, it went like this (lyrics may have been spelled differently):

Quick quack quannie onnie monnie monnie doshnick,
Quick quack quo,
quick quack quo.
Quick quack quannie onnie monnie monnie doshnick,
Quick quack quo,
quick quack quo.
Oh, Nickodemo, oh jolly-olly-ahmo,
Oh, Nickodemo, oh jolly-olly-oompa-oompa-oompa

Some of the pronunciations:

The words "quannie onnie monnie monnie" rhymed with the name Bonnie
The "doshnick" rhymed with the exclamation "Gosh Nick"
The j in jolly is not the usual j but a "zh" like in "measure"

Here is a rough sketch of the tune
The tune for the two long lines is exactly the same as the opening line in Rosemary Clooney's "This Ole House", such as:

    G     Bb   Eb      Eb    Eb     Eb      Eb  Eb
  "This   old  house   once  knew   my     children,"
  "Quick quack quannie onnie monnie monnie doshnick," 
  
  Then the next two lines are,
  
     G     Bb   A
  "Quick quack quo," 
     G     Bb   Eb
  "Quick quack quo." 
  
  The above lines are repeated, then the song moves to the refrain:
  
  [up one octave]
  Eb  Eb  Eb Eb C  Eb   D    C   Bb G
  Oh, Nick o demo, oh jolly-olly-ahmo, 
  
  Bb  C    Bb Bb F    Bb   C    D   Eb Eb Eb Eb Eb Eb <--Eb's octave down
  Oh, Nick o dem o, oh jolly-olly-oompa-oompa-oompa
  

Although I show all of the notes as of the same duration and have some notes covering a 2-syllable word, play them and you will get a good idea how the song was sung.

EuGene