LivingOrganisms had to track their display icon, be able to set it, and be able to present it when requested. Tracking the display icon involved re-defining the class, but that was really easy to do.
Object subclass: #LivingOrganism instanceVariableNames: 'ocean live x y display ' classVariableNames: '' poolDictionaries: '' category: 'FishWorld' LivingOrganism methodsFor: 'display' display Transcript show: display. display: displayCharacter display := displayCharacter.