Modifiers matching duck:

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

Simple categories matching here:

• activity,
• process,
• duck,