Reviving the thread because it's spooky season again and I couldn't help but put "Beware of the Zimwi" on repeat for a few plays. I didn't initially hate or even dislike the song, but it has certainly grown on me.
This isn't about the episode directly, but while I was listening to the song, I actually wanted to see if anyone had done any sort of creature design for the titular monster as per the show's description. (I know it's for preschoolers and it's supposed to be a bit cutesy, but I think it deserved a slightly creepier design.) Unfortunately I found little to nothing on DeviantArt - so there's plenty of room for artists to take a crack at it! - but Google Images brought up some interesting pictures (which linked to an extended commercial: https://vimeo.com/144212143) of a pretty cool-looking creature that was created for an ad campaign by a shoe company called Fila, who wanted to market a new shoe they called the Zimwi to African marketplaces. The creature itself actually looks pretty scary or at least intimidating -the bioluminescence is a nice touch that I really like - and its design kind of matches elements of Rafiki's song description: