Just mess around! Use the arrow keys to control the cat, g to toggle the griffin on and off, and e to do the same with the guitar and the pencil. Space to erase all. 1 and 2 to change size of cat, 3 to reset size. Feel free to remix and change the code - try other effects or different sprites.
All my own, though I got a bit of inspiration from Kalebot - https://scratch.mit.edu/users/kalebot/