Coulomb's feet are based on Rosie Rabbit's from Alan Dart's Animal Magic (sadly now, hard to come by because, yes, you've guessed it, Sirdar discontinued most of the colours.):
Coulomb's nose is actually Rosie's tail!
And Coulomb's hands are based on Gordon Gorilla's (same source):
(I've scanned in the pictures of the animals from Animal Magic. They're here.)
So the secret of Coulomb is that, instead of reinventing the wheel, I took bits of other patterns and adapted them to my needs (rather like Object Oriented Programming - oh yes, I have now linked knitting to computer programming!!).