Agent 3

Agent 3 of the New Squidbeak Splatoon refers to these characters who are or were known by that title:
 * Agent 3 (Splatoon), the player character of Octo Valley and a recurring character in the series who holds the role of Captain in.
 * Agent 3 (Splatoon 3), the player character of Return of the Mammalians who gets recruited under the same title in Splatoon 3.