Modifiers matching duck:

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

Simple categories matching here:

• process,
• duck,
• activity,