Modifiers matching duck:

• tenacious,
• here,
• jealous,
• indigenous,
• boastful,
• optimistic,
• native,
• slobbery,
• zany,
• insecure,
• rare,
• determined,
• domestic,
• lisping,
• breeding,
• aggressive,
• smaller,
• small,
• paranoid,
• marine,
• wild,
• brash,
• larger,
• large,
• daffy,
• unusual,
• bullying,
• pushy,
• short-tempered,
• common,

Simple categories matching daffy:

• person,
• billionaire,
• recluse,
• duck,
• philanthropist,