Ding Dong Daddy may not be a great villain, but the name is so evocative of the era, and the weird pseudo-60s slang that the Teen Titans spoke in, as written by Haney. Cardy's art is always superb, and Teen Titans 3 (May/June 1966) is no exception.
Batman gets a small role at the top of the story, as he and Robin chase a bank robber with a car that is even more high tech than the Batmobile. The crook gets away, and then Robin gets ordered to come to Washington DC with Aqualad, Kid Flash and Wonder Girl. This time around, they are asked to help deal with the problem of high school drop outs.
We get to see the Teen Titans helicopter in this issue. The Titans head to a small town where all the high school dropouts are getting hired by Ding Dong Daddu, who runs a car repair shop, which is a front for all manner of criminal activity.
It doesn't take the Teen Titans long to determine that Ding Dong Daddy was also the bank robber than Batman and Robin were chasing early on. The Titans go undercover, pretending to be drop outs in order to infiltrate Ding Dong Daddy's circle. and wind up with enough evidence to bring him down. The drop outs are so upset to find out how they have been used that they all decide to return to school, implausibly enough.
Although Ding Dong Daddy never returned, another character by that name appeared a couple of months ago in a Titans story.