I had recently steampunked up a Nerf Revolver and noted that the fart gun might look quite good with the same treatment.
Unfortunately, Teddy liked the gun so much that he kept it out in plain sight all the time. Indeed he used it so often that we had to replace the batteries.
So, I obviously couldn't just remove it to work on it....
Luckily, I was able to secretly buy another gun and, with a bit of planning and concealment, was able to present him with this as one of his Christmas Presents.