@Ednaelk - Sorry for being a little too late. Tom used to sing the song a capella, but since around 1980 he began singing it with the guitar.
I used to play it this way:
Am
Jennifer's rabbit, brown and white,
Em
Left the house and ran away one night
Am G
Along with the turtle and a kangaroo
Em Am
And seventeen monkeys from the city zoo,
Em Am
And Jennifer too.
C G
They ran through the forest and they all held hands.
Em Am
They came to the ocean with the cookie crumb sands.
C G
Called it the sea of the very best dreams,
Em Am
And they all built a castle of the best moon beams.
Em Am
And milky way streams.
However, I saw a concert video earlier this year, and discovered that Tom actually plays:
Am
Jennifer's rabbit, brown and white,
G
Left the house and ran away one night
Am G
Along with the turtle and a kangaroo
E7 Am
And seventeen monkeys from the city zoo,
E Am
And Jennifer too.
C G
They ran through the forest and they all held hands.
E7 Am
They came to the ocean with the cookie crumb sands.
C G
Called it the sea of the very best dreams,
E7 Am
And they all built a castle of the best moon beams.
E Am
And milky way streams.
If I remember correctly, he put the capo on the 6th fret, which makes the song in D#m.
I think both would work well - of course the original is better, though...
Jason