If you want Scratch-designed sprites, there is a button at the bottom of the screen labeled "import sprite" (or something like that). Click on it, and find the sprite you want.
If you want custom sprite, you can either make your own (click on the "costumes" tab and you can edit and create sprites there) or Google what you want.
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Also, on the Scratch website, there is a "support" link. I think there may be more sprites, sounds, backgrounds, etc. there.
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Click the "Import Sprite" button to import a new sprite. Click the "Surprise Sprite" Button to get a surprise sprite. Click the "Paint New Sprite" button to design your very own sprite.
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You can import any image, to use it as a sprite in Scratch.
You may also download other Scratcher's projects and use the sprites in them.
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