That link takes us to a student sign-in page for a website so we can't see the relevant page. However, this time, the link is sufficient.
A "take-off" is an imitation. In my opinion, it should have been followed by "of", not "on". Also, either the third "the" shouldn't be there or it should be followed by "show".
Among the activities in the zany show was a take-off of Who Wants To Be a Millionaire?
Among the activities in the zany show was a take-off of the show Who Wants To Be A Millionaire?
I find "activities" a bit odd there but as I've never seen this "zany show", I don't know if it's actually the appropriate word.