In his latest Bleat, James Lileks writes about a 'Cebu':

Anyone who has a kid who watches Veggie Tales might recognize the word; it’s from "The Song of the Cebu," a lethally catchy ditty about a boy in a canoe with three cows, or water buffalos, which the narrators calls Cebus. I have no idea if this is a word in any language, but when you listen to the song six times a day like I do, the word gets fused to the definition in the song. Gnat, too: show her a picture of a water buffalo, and she says Sayboo!

This cebu must be the creature more commonly called a zebu. Here is what Hilaire Belloc has to say about the beast, in the last poem of A Moral Alphabet:

Z

for this Zébu, who (like all Zebús)*
Is held divine by scrupulous Hindoos.

        MORAL

Idolatry, as you are aware,
Is highly reprehensible. But there,
We needn't bother -- when we get to Z
Our interest in the Alphabet is dead.

- - - - - - - - - - - - - - - - - - - - - - - - -

*Von Kettner writes it "Zébu"; Wurst "Zebu":
I split the difference and use the two.

I suspect nine out of ten readers had to read the last two lines of the Moral twice to get them to rhyme. The picture accompanying the poem seems to depict a hump-backed Brahma bull rather than a water buffalo.

My favorite poem in A Moral Alphabet is this one:

P

stands for Pig, as I remarked before,
A second cousin to the Huge Wild Boar.
But Pigs are civilised, while Huge Wild Boars
Live savagely, at random, out of doors,
And, in their coarse contempt for dainty foods,
Subsist on Truffles, which they find in woods.
Not so the cultivated Pig, who feels
The need of several courses at his meals,
But wrongly thinks it does not matter whether
He takes them one by one or all together.
Hence, Pigs devour, from lack of self-respect,
What Epicures would certainly reject.

        MORAL

Learn from the Pig to take whatever Fate
Or Elder Persons heap upon your plate.

I've quoted from an omnibus volume which includes Belloc's Cautionary Verses, The Bad Child's Book of Beasts, A Moral Alphabet, and more. The Cautionary Verses are the first two of seven volumes collected in one: they include "Jim, Who ran away from his Nurse, and was eaten by a Lion", "Rebecca, Who slammed Doors for Fun and Perished Miserably", and "Maria, Who made Faces and a Deplorable Marriage". The whole collection is highly recommended, not least for the pictures that accompany the verses. Unfortunately, it doesn't seem to be available in the U.S.

Note: I have emended the last (non-Moral) word of "P" to 'reject'. My copy reads 'eject', which seems unlikely: true Epicures rarely indulge in projectile vomiting if they can help it.