This project lets you record the mouse pointer coordinates over time, which you can use to animate the pen to draw stuff, or animate the motion of a sprite. Press "R" to start and pause/stop recording. Then click and draw with the mouse. Press "P" to make the pen draw what you recorded. Press "D" to delete the recorded data. See Notes and Credits for projects where I have used this technique. The recorded coordinates are stored in three lists, which you'll see if you look inside. You can either backpack the recorder sprite and drop it into your project, or record right here, export the lists to text files (by showing the lists on the stage, right-clicking on them, and srelecting "export"), and then import them into your project.
Projects in which I have used this technique: Snake Surprise (the game over animations): https://scratch.mit.edu/projects/402858855/ Badly Drawn Boy: https://scratch.mit.edu/projects/423926939/ Squirrel Drawing (the initial pencil drawing): https://scratch.mit.edu/projects/433982341/ Check out the studio "As if by magic" for lots of similar projects, each with a slightly different take: https://scratch.mit.edu/studios/6016341/
