On Beyond Zebra! is an illustrated children's book by Theodor Geisel, better known as Dr. Seuss

Dr. Seuss

Theodor Seuss Geisel was an American writer, poet, and cartoonist most widely known for his children's books written under the pen names Dr. Seuss, Theo LeSieg and, in one case, Rosetta Stone....

. This book fits into the genre of literary nonsense

Literary nonsense

Literary nonsense is a broad categorization of literature that uses sensical and nonsensical elements to defy language conventions or logical reasoning...

. The young narrator, not content with the confines of the ordinary alphabet

Alphabet

An alphabet is a standard set of letters—basic written symbols or graphemes—each of which represents a phoneme in a spoken language, either as it exists now or as it was in the past. There are other systems, such as logographies, in which each character represents a word, morpheme, or semantic...

, invents additional letters beyond Z

Z

Z is the twenty-sixth and final letter of the basic modern Latin alphabet.-Name and pronunciation:In most dialects of English, the letter's name is zed , reflecting its derivation from the Greek zeta but in American English, its name is zee , deriving from a late 17th century English dialectal...

, with a fantastic creature corresponding to each new letter. The creatures include favorites such as the Floob-Boober-Bab-Boober-Bubs, large buoyant heads which float serenely in the water. These naturally serve as the example for the letter "FLOOB".

Most of his letters look like monogram

Monogram

A monogram is a motif made by overlapping or combining two or more letters or other graphemes to form one symbol. Monograms are often made by combining the initials of an individual or a company, used as recognizable symbols or logos. A series of uncombined initials is properly referred to as a...

s of their names. In order, these are named YUZZ (Yuzz-a-ma-Tuzz), WUM (Wumbus), UM (Umbus), HUMPF (Humpf-Humpf-a-Dumpfer), FUDDLE (Miss Fuddle-dee-Duddle), GLIKK (Glikker), NUH (Nutches), SNEE (Sneedle), QUAN (Quandary), THNAD (Thnadners), SPAZZ (Spazzim), FLOOB (Floob-Boober-Bab-Boober-Bubs), ZATZ (Zatz-it), JOGG (Jogg-oons), FLUNN (Flunnel), ITCH (Itch-a-pods), YEKK (Yekko), VROO (Vrooms), and HI! (High Gargel-orum). The book ends with an unnamed letter that apparently is a monogram of all 26 letters in the existing Latin alphabet. It is left as an exercise in naming for the reader.

Some of the animals from On Beyond Zebra appear in the 1975 CBS TV Special, The Hoober-Bloob Highway

The Hoober-Bloob Highway

The Hoober-Bloob Highway is an animated musical special written by Dr. Seuss and produced by DePatie-Freleng Enterprises for CBS in 1975. The special is a musical, and features several songs written by Dr. Seuss and composed by Dean Elliott.Mr...

such as a Jogg-oon, a Sneedle, a Zatz-it, and a Wumbus.
These letters are not officially encoded in Unicode

Unicode

Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

, but the independent ConScript Unicode Registry

ConScript Unicode Registry

The ConScript Unicode Registry is a volunteer project to coordinate the assignment of code points in the Unicode Private Use Area for the encoding of artificial scripts. It was founded by and is maintained by John Cowan and Michael Everson...

 provides an unofficial assignment of code points in the Unicode

Unicode

Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

 Private Use Area for them.