Jellicle Cats

Jellicle Cats are the protagonists of Cats - throughout the musical, audiences meet different Jellicles and follow their exploits. Jellicle Cats are fictional domestic cats invented by T S Eliot. They are the feline counterpart to Eliot's Pollicle Dogs, whereby "Pollicle Dogs" is a corruption of "poor little dogs" and "Jellicle Cats" of "dear little cats".

Five-Finger Exercises
Pollicle Dogs and Jellicle Cats were first mentioned in a poem titled "Lines to a Yorkshire Terrier" from Eliot's short collection of poems, Five-Finger Exercises (1933).

In a brown field stood a tree

And the tree was crookt and dry.

In a black sky, from a green cloud

Natural forces shriek'd aloud,

Screamed, rattled, muttered endlessly.

Little dog was safe and warm

Under a cretonne eiderdown,

Yet the field was cracked and brown

And the tree was cramped and dry.

Pollicle dogs and cats all must

Jellicle cats and dogs all must

Like undertakers, come to dust.

Here a little dog I pause

Heaving up my prior paws,

Pause, and sleep endlessly.

Old Possum's Book of Practical Cats
Eliot later wrote a poem about Jellicle Cats titled "The Song of the Jellicles", which was published in Old Possum's Book of Practical Cats (1939). In this poem, Jellicles were depicted as commonly nocturnal black and white, scruffy cats. Specifically, Eliot mentions that they like to gather at an event called the "Jellicle Ball".

Eliot also wrote an unpublished poem titled "Pollicle Dogs and Jellicle Cats" which was used as the model for "Jellicle Songs for Jellicle Cats".

Cats
The Jellicles that we meet in the musical are a tribe of cats that, in contrast with "The Song of the Jellicles", possess many kinds of coat-patterns, diverse personalities, individual talents, and even magical powers. The tribe has its own established hierarchy, with Old Deuteronomy as the leader and Munkustrap as his second-in-command.

Theories

 * All cats are Jellicle Cats
 * Jellicle Cats refers only to this particular tribe of cats and many other similar cat tribes exist, similar to how the dogs have Pollicles, Pekes, Poms and Pugs
 * Jellicle Cats refers to a special type of cat that possesses human-level intelligence, magical powers etc. Other cats are just normal cats