In his own words. Looks like it was from 2011 (and best to have a copy here, in case it goes AWOL
www.dogandbear.org/profile/baloo
Why am I known as Baloo?
When I first became an Assistant Cub Scout Leader, my Cub pack choose what I was to be known as to the pack. I had no control over what they picked but was very pleased when they choose Baloo from the options available to them from the Jungle Book characters. I have always though it was good choice, using the original book character.
I continued to use the name Baloo outside of Scouting when I started to play wheelchair basketball to avoid confusion on court as there were already several other Davids (my real first name). It sort of made sense as the first team I joined was known as the Bears.
The name followed me when I was a volunteer helping with children's gymnastics and also when volunteering for the Coventry Half Marathon.
As I said above, I was quite happy with nickname and identified with the character from the book, so when I registered for parkrun, I used it again, partly because it was by now my volunteering / sporting nickname, and partly because it makes in much easier to find when looking through a long list of results (there might be quite a few results for David but not many for Baloo)!
When I was the Leader for the pack I became known as Akela as is traditional within Cubs but the Baloo identity never left me, to the extent the some of my Cubs decided to call me 'Aloo', and when I stepped aside from and went back to Assistant Leader, I resumed my Baloo name and am now one of the biggest kids in the pack.
Even my own children often call me Baloo, first just activities, but now even at home sometimes.
Once I started to run with Scooby Doo, a choice of fancy dress was not really difficult