Gobo is a sprite that comes with all installations of Scratch. With 20,176 uses on Scratch as of February 14, 2011, it is the ninth most common sprite used on projects uploaded to the Scratch Website (after buttonPressed). Gobo was named "Gobo" by Scratch Team member Natalie Rusk. 
A modified version of Gobo is used as the logo for the Scratch modification Build Your Own Blocks. It has a "tail" depicting the Greek lowercase letter lambda (λ), which, in computer science, represents the time window over which a process is observed for determining the working memory set for a digital computer's virtual memory management.