Fuzzles are natural creatures that the Vykkers capture to run tests on. Khan noticed that early Fleech designs resembled Fuzzles, so it's a kind of Forum belief that that's where their design comes from.
To find out about the next game, try reading all of these topics:
http://www.oddworld.au.com/forums/sh...&threadid=6778
http://www.oddworld.au.com/forums/sh...&threadid=6700
http://www.oddworld.au.com/forums/sh...&threadid=6342
http://www.oddworld.au.com/forums/sh...&threadid=6553
http://www.oddworld.au.com/forums/sh...&threadid=6575
And if you're going to ask single Oddworld questions that don't require much of an answer, I recommend putting them in TheKhanzumer's
Oddworld Questions and Answers topic, although kudos on not starting a new topic for your questions.