Croesus is a members achievement in the Skills category (Skilling Boss Croesus). It has no requirements.
In game: “Defeat Croesus. (X/1)”
0 RuneScoreSkillsSkilling Boss CroesusMembers
Updated 9 October 2026. From the RuneScape Wiki's achievement data (CC BY-NC-SA 3.0), checked 2026-10-09. Wiki page.
None: any account can do this one as soon as it reaches the right place.