Moop

A depressed or grumpy-looking cat

"What a sad moop you are! Has no one fed you any kitty food today?"

Wagglewoop

A cat that constantly follows at your heels and gets under your feet, sometimes resulting in you falling over it.

"Omg, little wagglewoop, stop trying to trip me up!"

Squoo

An exclamation of delight when you're reminded of something.

Essentially, a nostalgic "squee".

*wistfully* "Oh, squoo!"

"I squooed when I looked back at those pictures of us at Comic Con."