Each of the humans appears to have a fuzzly they are most closest with who helps them above all others. These are the ones I have noticed so far:
*Abby: Bozzly
*Lex: Terry
*Jeff: Curly
*Miranda: Flug
*Mrs. Melvin: Harriet
Am I missing any? In some cases it's just one episode (like with the parents) where it becomes apparent who each humans' counterpart.
Fuzzlies who I don't know of any matches for include the Peepers, Mo&Bo and Otis, but perhaps I just haven't seen the right episode for them yet? Unpaired humans are Melvin Melvin Jr / Melvin Melvin Sr, the Old Man... anyone else?