Alonzo ~ form of a Germanic name meaning "noble and ready"
Asparagus
Gus
Bustopher Jones
Munkustrap
Rum Tum Tugger
Plato ~ Greek scholar
Mistoffelees ~ Taken from 'Mephistopheles' which is another name for the Devil. Named after the devil, due to him being a magician, and at the time it was written, magic was considered to be evil.
Pouncival
Tumblebrutus
Mungojerrie
Old Deuteronomy ~ 'Deuteronomy' is a book from the Bible.
Skimbleshanks
Growltiger
Rumpus Cat
Coricopat
Macavity
Victoria ~Named after Queen Victoria
Rumpleteazer
Jemima ~ Little Dove
Electra
Etcetera ~ Means 'and the rest', showing that she is a background character.
Jennyanydots
Jellylorum ~ T.S Elliott had a cat called Jellylorum, and refered to her as his 'Lillie Cat'
Cassandra
Tantomile ~ A witches' cat.
Demeter
Bombalurina
Grizabella ~ Means 'grey' and 'beautiful'
Exotica