Modifiers matching duck:

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

Simple categories matching lisping:

• child,
• person,
• duck,
• villain,