graphics to possibly use?

what would be a good graphic for me to use with my courses this year, I have been thinking about a brand for my classes, something to help me make it interesting for more classes when I am doing powerpoint, moodle courses, internet pages, something that grabs students attention, previously I have had winnie, as well as a bee. Now I want something different and focused more around computing and design. ideas have been a robot, and toy story.