Mine get called "monkeys" and "mountain goats" too!
(hmmm...I guess you can deduce that they are little CLIMBERS! 
) KIKI:
The Kikinator
Kiki Monster
Fuzzy Britches
Fluffy Butt
(from which you can deduce that she is a ball of fur with major ATTITUDE! ) MAZIE:
Mazie Mae
Madle (rhymes with "ladle"...not sure WHY I started that!)
Street Urchin
Gutter Rat
(she was our pathetic little rescue project, and still tends to look scrawny and scraggly at times, so... )
---Together I tend to call them "The Jingaling Twins": for safety I keep bells on them, and you can always hear them coming!