The Cat walking in the long grass is a project that takes a backdrop and uses a part of it as a sprite in the foreground. How is it done? See below and see inside. How many other backdrops can you find in the library that can be used in this way? Creatively, you could hide other sprites in the grass as a part of a game.
How to make a 'grass' sprite from the Forest backdrop. 1. Set the Forest as a backdrop. 2. Bring up the backdrop tab. 3 (In Graphics Editor) export the backdrop to your computer. 4. Import the forest as a sprite. 5. Click the Costumes tab and (In Graphics Editor as a bitmap) use the eraser tool to erase the pixels. (See the project: Cat in the NextRoom at 342394548)