Here’s one I had never heard of before – a Genial Lucifer!
The seller of this example notes that it comes with a 100cc two-stroke motor and that it was built in Paris, France – based on the first statement I’m guessing that it’s a BMA engine with a 2-speed transmission. BMA stands for Bicyclette Moteur Auxiliaire, which was a French category of motorcycles that were exempt from tax or registration. As stated by Sheldon’s EMU, the designation was introduced in 1926 and the rules were that the engine had to be <100cc, the total package had to weigh under 30 kg, it had to have pedals, and it had to have a top speed of less than 30 kph.
It does not currently run, however the motor turns over and the "bike seems to be all original and untouched." Have fun finding parts - but you won't have to find the tool kit as that's included!
Find this Lucifer (what a name!) for sale in Rincon, Georgia with an unmet opening bid of $2,000 here on eBay.