The Whozagiggawhat

It's a magical creature with huge girlish eyes.
It lives in the sewer and flies through the skies.
It swims through the sewer with its big propeller head,
having so much fun that it never goes to bed.
Down in the sewer with its big, blue beak,
its big blistered back makes it look like a freak.
You'd think it couldn't walk with it's big flipper feet,
while munching through the sewer for a tasty treat to eat.