Some frizzles just feather in slowly...usually seems to be the boys. I have one that looked like that until he was a few months old. I know for a fact only 1 of his parents was a frizzle b/c the person I bought the eggs from doesn't even own a frizzle roo. His name is Baldy.
Then:
Now:
ETA: Ignore the dates on the pics...I can never get the darn thing set right.