ABC Batgirl Promotional Short, 1967
The rarely seen 8 minute long Batman season three promo from 1967, in which we first see Yvonne Craig as an unreasonably hot librarian who somewhat cumbersomely transforms into an unreasonably hot superhero-type person. Originally used as a vie by Batman producers to get Batgirl into the show, the suits liked it enough to use it as an extended commercial.
Batgirl Promotional Short, Part One [tvobscurities]