Yet Another Zombie Survivors Easter Egg Item Guide

Easter Egg is the reward linked to Curly Little Potato; if it produces Black Box during Prologos, update to 1.0.1b or later so that collection counts. The official hotfix confirms that route. If the mission still appears incomplete, check the mission troubleshooting steps before replacing a save.

Follow the reward route

Use the Curly Little Potato guide for the linked achievement route. The Version 1.0 release changed that achievement reward to Easter Egg. Unlocking a reward and having its random effect produce a particular item are separate steps.

If you need Black Box for Prologos

Keep the mission selected, update to 1.0.1b or later and check the Mission Log. If Easter Egg produces Black Box during the attempt, the hotfix says it counts toward the objective. If the log remains incomplete, record the item source and mission state for the developer rather than assuming the entire save is lost.

For this task, prioritize completing the collection objective over a combat-item swap. The mission troubleshooting guide linked above helps separate collection recognition from missing mission offers.