cygnet
A young swan before it gets its adult feathers.
A cygnet is a young swan, from the time it hatches until it grows its adult feathers. While adult swans are famous for their elegant white plumage and graceful long necks, cygnets look quite different: they're covered in fluffy gray or brownish down feathers that help keep them warm.
You might remember the word from The Ugly Duckling, the Hans Christian Andersen story about a cygnet who feels out of place among ducklings. The poor cygnet thinks he's ugly, but he's actually just a young swan who hasn't grown into his beauty yet.
Cygnets stay close to their parents for several months, sometimes riding on their mother's back when they get tired of swimming. By their first winter, they begin developing their adult feathers, though some swan species don't turn completely white until their second or third year. Swan families are remarkably devoted: both parents help raise their cygnets, teaching them where to find food and how to navigate their lake or river home.