jabba the hutt was originally a human

The original

The finished version

check it out - Jabba was originally a stout Irish man and then they CGI'd him into a slug. the only thing they had a hard time working out was when Hans Solo walked behind him - he would effectively have to walk over his tail - and you can see they make a big deal out of it - Jabba squelling in pain.
WOW - you learn a new thing everyday.