Q. re. Max Fleischer cartoon Bimbo's Initiation

Despite the multitudes of references a search brought up, I’m having difficulty pinning down this bit of trivia: What was the name of the secret society that kept pestering him to be a member?

“The Mystic Order of the Koo-koo Mama Hotcha Koo-koo Mama Hotcha Koo-koo Mama Hotcha,” as near as I can make out.

Good luck finding the spelling from an authoratative source, though.

Bright Lights Film Journal.

That version also crops up on several Betty Boop sites.

Sounds like “Boom Boom a Hot Cha” to me. http://www.youtube.com/watch?v=RFrBG4xyaF8#t=0m43s

From the rhythm pattern in the orchestra before the singing starts, there might be another “a” between the “booms”.

“Hot Cha” was a phrase popular around that time. For example, see The Hot Cha Melody (1935) The Hot Cha Melody (Short 1935) - IMDb