Robbie's immaturity can be seen in certain childish behavior, fear and lack of development. He’s afraid of the dark, he often jumps when surprised and when confronted or exposed he slinks away with embarrassment. Robbie has little to no idea of how to act in social situations. When he attends Ziggy's birthday party, he’s unsure of how to behave or act around others. Robbie often displays malevolence towards others, having a desire to ruin their fun and to teach them a lesson.