The Scratch Cat is the mascot of Scratch and the default sprite when opening a new Scratch project. This can't be changed. It is also the outline for the default icon of new Scratch accounts, replacing a previous version that showed a human silhouette.
The Scratch Wiki is a free, collaboratively-written wiki that provides information about the Scratch programming language and its website, history, and phenomena surrounding it. The wiki is supported by the Scratch Team, but is primarily written by Scratchers. The Scratch Wiki is a popular source of information for scripts and tutorials, and it continues to grow as Scratchers use it as their primary source of information.