Long-necked bird with a "knob" on its beak

SWAN

Think of a graceful waterfowl often linked to fairy tales and royal symbols.

This clue describes a swan, which is known for its long, graceful neck. The mention of a "knob" refers to the black bump at the base of a male swan’s beak, called a basal knob, which helps identify it as a mature cob (male swan). The wordplay is straightforward—no tricks—just a clear physical trait that points directly to the answer.