Apparently, this is not an error. Leibniz biscuits are indeed named after Gottfried Leibniz by the Bahlsen confectionery company which makes them!
A full FAQ on the subject is available on the Bahlsen website. Here’s some pertinent information translated straight from the german FAQ.
1) Company founder Hermann Bahlsen created “Leibniz Cakes” in 1891, naming it after one of the most famous inhabitants of Hanover, Gottfried Wilhelm Leibniz (1646-1716). To identify foods after famous people was not uncommon at that time (eg Bismarck herring, Schiller’s hair, Mozart ball).
2) Leibniz Butter Biscuits have “52 teeth” for purely aesthetic reasons. Hermann Bahlsen found that with this number, the cookies had the best appearance. Only genuine Leibniz butter biscuits have 52 teeth. If you are puzzled as to what teeth are, go count the notches on the edges of this biscuit.
3) On the issue of teeth, other Leibniz products have a different number. “Leibniz whole grain” and “Leibniz Landkeks” have only 38 teeth. This is due to the consistency of the dough that is slightly coarser than the type used for butter biscuits. The teeth must therefore be greater in size or they would break too easily. The “Choco Leibniz” has 48 teeth, because being covered with chocolate, the underlying cookie is slightly smaller than the normal butter biscuit version. The overlaying chocolate layer does however have 52 teeth. “Leibniz Minis” have exactly half of the teeth (26) of a butter biscuit.
4) On the issue of the animals in the “Leibniz Zoo” series, zoo packs contain 17 different animals: rhino, turtle, sheep, owl, penguin, monkey, squirrel, rabbit, duck, camel, cat, elephant, lion, bear, dog, donkey, horse. The ratio of species per pack of “Leibniz Zoo” is not always the same for technical reasons. While the animal forms are represented in equal proportion, after baking, the cookies arrive in a single mix to be filled into packs. Thus, the number of individual animal per pack will be distributed by random chance.
5) If you would like a “zoo” scrapbook, send a stamped 55 cents A6 envelope with your address to: Bahlsen, 30001 Hannover.