I saw these on X and wanted to post them here on the forum. Evidently, these are claimed to be very early sketches of what a "Batman 3" logo Warners were considering for what later became "Batman Forever".
(https://pbs.twimg.com/media/GBqucE4akAA9Hgg?format=jpg&name=900x900)
(https://pbs.twimg.com/media/GBquchybEAAipI7?format=jpg&name=900x900)
(https://pbs.twimg.com/media/GBquc8FaEAAACEX?format=jpg&name=900x900)
(https://pbs.twimg.com/media/GBqudL5bYAAaSKT?format=jpg&name=small)
Also, the "B3" logo supposedly got as far as caps being produced for crew members working on the film.
(https://pbs.twimg.com/media/GGVVnxkaUAAaxa2?format=jpg&name=large)
(https://pbs.twimg.com/media/GGVVqa7bgAAa6tj?format=jpg&name=large)
Personally, I don't think any of these possibilities really holds a candle to what they eventually went with with the question mark/bat logo, but it's interesting to look at nevertheless.