With the popularity of robotics education, attention has been drawn to students' perceptions of robots. This study provides a framework to understand students' imagination about and perceptions of robots from four dimensions of robot identity--nature, social, emotional, and evolutionary. We applied the framework on 80 literary products generated by 16 sixth-grade students in a course that integrated robotics programming and literacy, such as writing and drawing about their imagination of future robots, and digital comics developed from their stories about robot. The analyses revealed a wide range of variation in terms of robot identity and the robot's overall resemblance to human.