Beh-Heh?

I definitely remember Sweet Tooth. Filmation had actually animated Batman twice. The cartoon of this page is the very first one. It aired back in 1968 not long after the live TV series had cancelled. This is the very first animated Batman series ever made and is surprisingly not on DVD. Olan Soule and Casey Kasem were the voices of Batman and Robin and later voiced them over on the SuperFriends as well. Ted Knight was Alfred, Commissioner Gordon, the narrator, and all the male villains and Jane Webb was Batgirl and Catwoman. This is the cartoon where the episodes were 6 minutes each and half of them were 2 parters. All the popular villains along with several new ones were on here like Simon the Pieman, Dollman, and the Judge. We also saw the Mad Hatter and the Scarecrow. This was the show where Batman and Robin would actually punch the villains.
You mentioned Clayface and Sweet Tooth. They were on the second Batman series Filmation produced a decade later in 1977. The New Adventures of Batman was virtually the same series in all respects except that Adam West and Burt Ward were the voices of Batman and Robin. While the Joker and Penguin remained the same, Catwoman and Commissioner Gordon looked different (and better). Alfred was replaced by BatMite (Lou Scheimer voiced him over). The episodes had no narration and were a half hour long. Only 16 episodes. Clayface replaced the Riddler, who along with the Scarecrow at the time were part of the Legion of Doom on Challenge of the SuperFriends in 1978. Newer villains like
The Moon Man, Sweet Tooth, Professor Bubbles, the Chameleon, and Zarbor were created for this show. In this series, no punching was allowed, so Batman and Robin fought with their Bat Devices in their utility belts. Surprisingly, this series IS available on DVD, but not the first series. Anyway, hope this helps and answers your questions.
Cheers.