That's quite the doodle you've created! It'll certainly be a nice little surprise for the buyer and their daughter.

I hope so! I wanted to include a little drawing inside too, but we were in a rush to get it to the post box.

All things considered, I'd say you did an excellent job! If I were the one receiving a package with such art on it, I'd definitely keep the envelope for artistic value - Hell, I might even have it framed.

I actually did something similar once - I was sending a friend some games I no longer needed (on account of my 360 doing the ever-popular "cook itself to death" trick), and since they requested I hand-write them a letter to go with it, I doodled their fursona as Commander Shepard. It certainly didn't hold a candle to your own efforts, though.