Interesting. Your post got me to finally look up the history of this [1]. Apparently it was a woman with an umbrella in a 1975 study, but made extreme by Simons in 1992 with the gorilla. The moonwalking bear is apparently from a 2008 Transport for London advertisement [2] to remind people to see cyclists.

[1] https://en.m.wikipedia.org/wiki/Inattentional_blindness

[2] https://www.theguardian.com/uk/2008/nov/16/transport-invisib...