Modifiers matching duck:

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

Simple categories matching insecure:

• child,
• pianist,
• criminal,
• person,
• autocrat,
• network,
• system,
• narcissist,
• teenager,
• transport,
• son,
• friend,
• comedian,
• psychopath,
• fool,
• composer,
• bully,
• humorist,
• dictator,
• heroine,
• singer,
• politician,
• medium,
• actor,
• president,
• thug,
• physicist,
• actress,
• student,
• director,
• snob,
• psychiatrist,
• writer,
• tyrant,
• queen,
• clown,
• princess,
• duck,
• nerd,
• father,
• musician,