Claude Opus 5's implementation design for the ARG creature Easter eggs demonstrates a sophisticated separation-of-concerns pattern: creature lore lives exclusively in the footer (site-wide HTML) and CLI name-triggered responses (runtime), while the core puzzle bank of 1,867 validated bridge pairs remains untouched. This architectural decision ensures that no invented words enter the game's compound-word validation system, preserving the fundamental rule that every join must be a real English compound. The same pattern could serve as a template for any future cross-project content integration that must not compromise core data integrity.