This was my kitty named "Jethro", but I called him "Poom-Kee". The derivation of his nickname goes something like this:

Kitty > Kitty puss > Kitty pussum > Kitty pussum cat > Kee puss > Pussum cat >
Pussum Kitty >
Poom-Kee.

He lived to be 21 years old, from the time I was eleven until I was 32. I started calling him "Methuselah".

"Choo-Chee" my mom's poodle. She was a great little dog, incredibly smart, but as a young boy, I never could get past the "poodle thing."  I have a great deal of guilt about this, it was my loss.
Other names for Choo-Chee included; "Smerchins > perchins > foots and pertifuls >squirty toots...and so on"

I have a bird now named "Smeeter". There is a similar methodology to his naming:
Tweet > Tweety > Tweety-bird > Tweets > Smeets > Smeety-bird > Smeety > Smeet >
Smeeter.