Define
A recurring character who personifies a duty. Not a one-shot cartoon. A resident conscience.
Mechanism
Personified obligation. The mascot can repeat the ask across years without the message feeling like a new campaign each time.
Verdict
The behavior must be taught for years (safety, conservation, hygiene) and a face helps people remember.
Don't
The ask is a single promotion. A mascot for a weekend sale is a costume, not this pattern.