SirPHLC,
P/O Percy Prune was the creation of Bill Hooper a cartoonist of some reknown. He started his RAF service early during WWII and served on 54(F)Sqn as groundcrew. A short time later he found himself seconded onto the staff of 'Tee Emm' which was the RAF's 'Airclues' of the day and proceeded to expand on the character of Prune and a whole collection of fellow incompetents to illustrate the message of Flight Safety' to a wartime RAF. If you can find example of Tee Emm I recommend you read them as not only are they hysterically funny but the message hasn't changed in 60 years. Also Tee Emm awarded TMHDAOTIF (The Most Highly Derogatory Award of the Irremovable Finger) to the most amusing flight safety or aviation related idiot of the month.
Examples that stick in my head are the Beaufighter night fighter pilot who spent some time circling a red light on the ground until he realised it was his port nav light, and the Spitfire pilot who on being questioned by his boss why his taxi speed was so excessive replied by saying that as his fuel was low he wanted to ensure he got back to his dispersal before running dry!