It's in the 1969 episode Decoy For A Dognapper. At one point Velma and Shaggy are lost in an underground hideout. A bunch of bats get startled and they start flying around them. As they're waving their arms and trying to avoid the bats, Shaggy says "If I ever get out of this, we'll call this dance the Batusi".
Batman reference in Scooby Doo
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Batman reference in Scooby Doo
“What's important is that the world know that all visitors to these teeming shores are safe, be they peasant or king.”