The rhyme known as Cree Craw toad's foot to most fans of The Pretender is the nursery rhyme Jarod was repeating as a boy when he was first under observation by The Centre after he had built a model of the Empire State Building in record time. He has also repeated the rhyme in other episodes, notably, Crazy.
There are only two lines of the rhyme known or ever repeated in The Pretender. It is unclear whether there are more lines or verses.
Geese walk barefoot
Cree craw toad's foot
According to a note on TV.com, the origin of the rhyme is from an old German lullaby.